The Significance of the Number Eighteen

By Rabbi Dr. Hillel ben David (Greg Killian)


In this study I would like to examine the significance of the number eighteen (18).


According to the gematria, the Rabbinic system of numerical symbolism, each letter of the Hebrew alphabet represents a number. The word chai -                  חי meaning life consists of two Hebrew letters het - ח equivalent to the number eight, and yud - י equivalent to the number ten which together add up to 18.


ח – 8

י  - 10


Total = 18


The main thing that we can learn from 18, Chai, is the fulfillment of Torah and commandments (mitzvot), as in the verse:


Vayikra (Leviticus) 18:5 Ye shall therefore keep my statutes, and my judgments: which if a man do, he shall live in them (mitzvot): I HaShem.


Eighteen means your performance, the full extension. Eighteen is life!


Eighteen represents a basic structure of life.


Matza and Eighteen


Both bread and Matza are flour mixed with water, then kneaded into a dough and baked. What is the difference between them? The difference is that bread dough has sat unattended for eighteen minutes and becomes leavened (bread). The Matza which we eat on Passover has been baked quickly.


Eighteen is the amount of time it takes to turn matza dough into chametz (leaven). It is the difference between being cut off from the those who live (keret), during Pesach, and those who actually live.


The spelling of “Matza” is similar to “mitzva:” Just as we shouldn’t delay in the making of Matza, so too we shouldn’t procrastinate in performing a mitzva. The lesson of Matza is to seize the moment. Delaying even one second can mean the difference between an opportunity gained or lost.


Why eighteen minutes? Because the number eighteen is the numerical value of “Chai,” meaning “life.” They say that “baseball is a game of inches”. Actually, life itself is a game of seconds. The Talmud tells of people who had sunk to the depths of humanity, and then in one moment of insight reversed their lives for all eternity. More than just the difference between Matza and bread, the Seder teaches us the difference between life and death.


Eighteen In Our Prayers


Eighteen is the number of times HaShem’s name is mentioned in shema[1]. When we declare the unity of HaShem we are connecting to The Source of life.


The number eighteen is prominent in the eighteen blessings of the Shemone Esreh. The Shemone Esreh is called The Prayer, The standing prayer. It is the quintessential service of life. We live to serve HaShem.


The number eighteen is prominent in the song sung by the Jewish People after the splitting of the Red Sea (Exodus 15:1-19).


Midrash B’Midbar Rabba to Numbers  2:1-34 AND THE LORD SPOKE UNTO MOSES AND UNTO AARON, SAYING (Num. II, 1). In eighteen passages you find Moses and Aaron placed on an equal footing (i.e. the divine communication was made to both alike); to this the Eighteen Benedictions correspond (the reason, was that Moses and Aaron were both instruments of Israel’s deliverance, which would not have been effected without their prayers, hence the daily Prayer was likewise divided into Eighteen Benedictions.). From the three Patriarchs you derive the fixed ritual of praying three times a day. Abraham instituted morning prayer, as it is said, And Abraham got up early in the morning to the place where he had stood, etc. (Gen. XIX, 27), and standing signifies prayer, as it is said, Then stood up Phinehas, and prayed [English Version: ‘wrought judgment’] (Ps. CVI, 30). Isaac instituted afternoon prayer, as it is said, And Isaac went out to meditate in the field at eventide (Gen. XXIV, 63), and ‘meditation’ signifies prayer; as it is said, A prayer of the afflicted, when he faints, and pours out his meditation (E.V.: complaint) before the Lord (Ps. CII, I). Jacob instituted evening prayer, as it is said, And he lighted (wayyifga’) upon the place, etc. (Gen. XXVIII, 11), and pegi’ah signifies prayer, as it is said, Therefore pray not you for this people ... neither make intercession (tifga’ - all three are from the root paga’) to Me (Jer. VII, 16). In eighteen passages Moses and Aaron are conjoined, thus giving a hint for the Eighteen Benedictions which correspond to the eighteen references to the Divine Name occurring in the shema’ and in [the Psalm commencing,] A Psalm of David: Ascribe unto the Lord, O you sons of might (Ps. XXIX, 1). The three Patriarchs, then, introduced the custom of praying three times a day, while from Moses and Aaron and from the above-mentioned references to the Divine Name we infer that eighteen benedictions [must be said].


Chazal instituted Eighteen Benedictions of the Prayer (the Tefillah), corresponding to the Eighteen mentions [of the divine Name] in the Reading of the Shema, and also in [the Psalm], Ascribe to the Lord, O you sons of might (Psalm 29):


Tehillim (Psalms) 29:1 <<A Psalm of David.>> Give unto HaShem, O ye mighty, give unto HaShem glory and strength. 2  Give unto HaShem the glory due unto his name; worship HaShem in the beauty of holiness. 3  The voice of HaShem is upon the waters: the God of glory thundereth: HaShem is upon many waters. 4  The voice of HaShem is powerful; the voice of HaShem is full of majesty. 5  The voice of HaShem breaketh the cedars; yea, HaShem breaketh the cedars of Lebanon. 6  He maketh them also to skip like a calf; Lebanon and Sirion like a young unicorn. 7  The voice of HaShem divideth the flames of fire. 8  The voice of HaShem shaketh the wilderness; HaShem shaketh the wilderness of Kadesh. 9  The voice of HaShem maketh the hinds to calve, and discovereth the forests: and in his temple doth every one speak of his glory. 10  HaShem sitteth upon the flood; yea, HaShem sitteth King for ever. 11  HaShem will give strength unto his people; HaShem will bless his people with peace.


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-Said R. Hiyya b. Abba: [The eighteen times ‘command’ are counted] only from “And with him was Oholiav, the son of Ahisamach of the tribe of Dan.” (Exodus 38:23) until the end of the Book.


The phrase “as HaShem had commanded Moses,” appears eighteen times in Torah portion Pekudei. The Talmud[2] asks the following question: Why do we say eighteen blessings in the daily Shemoneh Esrei prayer? Some of the answers the Talmud records are as follows: “Rabbi Shimon says that the eighteen blessings correspond to the eighteen discs in one’s spinal chord. Rabbi Chaninah says in the name of Rabbi Pinchas that the eighteen blessings correspond to the eighteen times that our forefathers (Abraham, Isaac, and Jacob) are mentioned together in the Torah. Rabbi Shmuel bar Nachmani says in the name of Rabbi Yochanan that the eighteen blessings correspond to the eighteen times the phrase ‘as HaShem had commanded Moses’ appears in the Torah portion of Pekudei.”


All of the reasons mentioned above can be combined into one central idea: One of the things that differentiates man from animal is the fact that he is able to walk upright, that he has a spine full of vertebrae. The mark of someone who is a ba’al ga’ava, a haughty person, is that he walks with a straight spine, upright, in a way which shows that he feels greater than everyone else. A humble person, however, tends to walk more bent over, in a submissive manner, realizing his lowliness in comparison to his Creator.


One foundation of prayer is for us to realize that we are totally subjugated to HaShem; only He can give us what we need and has given us what we have. Three times a day during our recital of the Shemoneh Esrei prayer we bow to HaShem as we say the words “Baruch ata -- blessed are you.” We then stand upright when we say “HaShem”, recognizing the blessing HaShem provides man by straightening the bent. A Jewish king is required to recite the entire Shemoneh Esrei prayer while on his knees, to show himself and the entire Jewish people that even the king is totally subjugated and dependent on HaShem.


Another foundation of prayer is zechut avot, the merit of our righteous forefathers: Abraham, Isaac, and Jacob. Their deeds and self-sacrifice are the only reason we have the opportunity to stand before HaShem. Without them, we would be like any other nation, devoid of the special relationship our forefathers achieved to connect to the Infinite.


The central idea which connects the reasons of the bent spine and our forefathers’ righteousness can be found in the third reason mentioned above as to why we recite eighteen blessings in the daily Shemoneh Esrei: “as HaShem had commanded Moses,” the phrase which is repeated eighteen times in this week’s Torah portion. Moses did just as HaShem commanded him, and so did our forefathers. We, too, because of their merit, are able to serve HaShem by bowing our spine and subjugating ourselves to His will, as we do every time we recite the Shemoneh Esrei prayer.


Berachoth 28b GEMARA: On what are these “Eighteen Blessings” based? Rabbi Hillel the son of Rabbi Shmuel Bar Nachmani says that they’re indicated by the eighteen times the name of God is mentioned in Psalm 29, “Bring to God, you sons of the mighty”. Rabbi Joseph bases it on the eighteen times God’s name is mentioned in the Shema. Rabbi Tanchum said in the name of Rabbi Yehoshua Ben Levy that the eighteen blessings correspond to the eighteen major vertebrae in the human spine.


Many attempts to uncover the underlying structure of the Amida are predicated on the significance of the number eighteen in the “Eighteen Blessings.” These attempts include the drawing of correlations between the eighteen blessings and the eighteen vertebrae of the spine, eighteen matters of the Sanctuary, eighteen pivotal events in Jewish history, or eighteen select biblical texts. R. Saadya Gaon came up with twelve different reasons for this number of blessings.



QUESTION: The Gemara describes three reasons why the Hakhamim instituted eighteen blessings in the Shemoneh Esreh.

(a) They correspond to the eighteen times that the name of HaShem is mentioned in Tehilim 29.

(b) They correspond to the eighteen times that the name of HaShem is mentioned in the three paragraphs of Shema.

(c) They correspond to the eighteen vertebrae of the spine. Is there anything common to these three groups of eighteen?


ANSWER: The SEFER HA’IKRIM (1:5) says that the three main tenets of Jewish belief are that

(a) HaShem created the world;

(b) HaShem gave us the Torah and commanded us to follow the Mitzvot;

(c) HaShem sees and knows all of man’s actions and will reward and punish appropriately in the World to Come.


It could be that these three tenets are included in the Shemone Esreh according to the three reasons given for why the Hakhamim instituted eighteen blessings.

(a) The verses of Shema declare HaShem as the One and Only Creator.

(b) Tehilim 29 describes the events of the giving of the Torah, and therefore represents our belief that HaShem gave us the Torah .

(c) The spine represents the knowledge that HaShem sees all of our actions, because the spine is the part of the central nervous system that directs every action and movement that a person makes, which are being watched by HaShem. In addition, HaShem will take one vertebrae from the spine and rebuild the body from it at the time of the resurrection. The spine therefore alludes to the belief that HaShem will give eternal life to those who follow His ways[3].


These three illustrations appear to correspond to the three parts of man’s Soul; the vertebrae [Nefesh - physicality]; the Keri’at Shema [Ru’ach - Spirit, with which we praise HaShem]; “Havu la’Shashem B’nei Eilim” (which refers to Matan Torah) [Neshamah - the most spiritual of the three Souls]. This teaches us that, when we stand before HaShem, we must pray to him at all three levels.


The Hallel and Eighteen


Ta’anith 28b R. Johanan said in the name of R. Simeon ben Jehozadok: “Eighteen times during the year an individual may recite the whole Hallel, and they are:


On the eight days of the Feast of Tabernacles,

on the eight days of the Feast of Dedication (Chanukah),

on the first day of the Passover, and

on the day of Pentecost.


While in exile, however, one may recite it twenty-one times during the year, namely: On the nine days of the festival of Tabernacles, on the eight days of Chanukah, on the first two days of Passover, and on the two days of Pentecost.”


Eighteen in the Mishkan


If we would list the materials for the offering for the Mishkan, there would be eighteen different items:


Shemot (exodus) 25:1-7 And this [is] the offering which ye shall take of them; gold, and silver, and brass, And blue, and purple, and scarlet, and fine linen, and goats’ [hair], And rams’ skins dyed red, and badgers’ skins, and shittim wood, Oil for the light, spices for anointing oil, and for sweet incense, Onyx stones, and stones to be set in the ephod, and in the breastplate.


Said R. Samuel b. Nachman in the name of R. Nathan: Eighteen times is [‘As the Lord did] command’ written in the section of the Tabernacle:  Exodus 37:22; Exodus 38:1, 5, 7, 21, 26, 29, 31, 32, 42, 43; Exodus 40: 16, 19, 21, 23, 25, 27, 29, 32.


The Ba’al HaTurim[4] points out the seemingly redundant repetition of the phrase, “As HaShem commanded Moshe” after each item for the Mishkan was constructed. He explains that as a reward for Moshe’s pleading for the Jews after the sin of the Golden Calf, when he said, “Please erase me from your book”, HaShem constantly repeats Moshe’s name in this portion. The Ba’al HaTurim notes further that the phrase “As HaShem commanded Moshe” appears eighteen times in this portion, corresponding to the eighteen blessings of the weekday Amida. The phrase, “As HaShem commanded, so they did” appears once, and corresponds to the additional nineteenth blessing against heretics. How are these three ideas - Moshe’s pleading, the Amida, and the construction of the Mishkan - related?


The Torah repeats the phrase, “As HaShem commanded Moshe” eighteen times, to show that the Mishkan was constructed with the same selflessness which Moshe embodied. The only purpose was to fulfill the will of HaShem. Similarly, in prayer, we should strive for this commitment to serving HaShem. We do not make requests of HaShem for our own pleasure, but so that we will be better able to perform the will of our Creator.


Oftentimes a good way to get to know someone or something is to investigate its name. The Gemara jumps in to do just that. Rabbi Hillel the son of Rabbi Shmuel notices that the Divine name is mentioned eighteen times in the 29th Psalm, most often related to Kaballat Shabbat (Welcoming the Sabbath) and reading to Torah. In other words, he’s telling us that our daily prayer corresponds on a very deep level to both the Shabbat and to the Torah. Rav Yosef brings us a new connection, this time with the Shema which also contains eighteen repetitions of the Divine Name. The Shema, as we already know, is the central declaration of the Unity of All. Thus in this prayer we approach all that there is which is now further linked with the realm of Shabbat and with the Torah.


Eighteen In The Body


Rabbi Tanchum, in the name of Rabbi Yehoshua Ben Levy, points out another occurrence of “eighteen” in the primary vertebrae as seen in medieval anatomy (in fact there are additional cervical and tail vertebrae, but the largest set actually does contain eighteen!). The spine! The structure that stands us upright, makes us, in a certain way, human. The spine also represents the vav in the Divine Name, the connector between the upper and the lower realms. The prayer of Eighteen engages us in the ultimate service of life: Bowing to HaShem in prayer.


The spine represents the knowledge that HaShem sees all of our actions, because the spine is the part of the central nervous system that directs every action and movement that a person makes, which are being watched by HaShem. In addition, HaShem will take one vertebrae (the luz bone) from the spine and rebuild the body from it at the time of the resurrection. The spine therefore alludes to the belief that HaShem will give eternal life to those who follow His ways.


Zohar 821 Lulav is Righteous One, NAMELY, YESOD, for the Lulav is like the spinal chord that contains eighteen vertebrae, corresponding to the eighteen shaking movements with the Lulav. And they correspond to the eighteen blessings of the Amidah prayer, and they correspond to the eighteen mentions, NAMELY, THE NAMES OF YUD HEI VAV HEI, in “Ascribe to HaShem, O you mighty” (Tehilim 29:1), and the eighteen times that the Divine Name is mentioned in the recital of the Sh’ma. And the Lulav is shaken in six directions: SOUTH, NORTH, EAST, UP, DOWN AND WEST, which makes six, and it is shaken three times in each direction, MAKING a total of eighteen.


Eighteen and the Menorah


Bamidbar (Numbers) 1:1 has eighteen words in Hebrew. These resonate with the fact that the Menorah was to be eighteen handbreadths in height:


Menachoth 28b Samuel said in the name of an old scholar, The height of the candlestick was eighteen handbreadths: three handbreadths for the base and the flower upon it, two handbreadths plain, one handbreadth for cup, knop and flower, again two handbreadths plain, one handbreadth for a knop out of which two branches come forth, one on each side, extending and rising to the same height as the candlestick, then one handbreadth plain, one handbreadth for a knop out of which two branches come forth, one on each side, extending and rising to the same height as the candlestick, then again one handbreadth plain, and one handbreadth for a knop out of which two branches come forth, one on each side, extending and rising to the same height as the candlestick, and then two handbreadths plain; there now remained three handbreadths, in which space were three cups, a knop and a flower.


The same may be learned from the cleansing procedure. The cleaning could have been done without recourse to a set of steps, because the Menorah was only eighteen tefachim (approximately five and one-quarter feet) high. If we could rely on presumptions and evaluations, a cleaning done from ground level would allow us to confidently say the Menorah is perfectly clean and ready. But we may not rely on anything, and we must know absolutely, by looking downwards into the lamps, that they are perfectly clean and ready. Similarly, when we teach others to avoid sin and develop good character traits, we must do so fastidiously and with perfectionism.


Marriage At Eighteen


The Mishna indicates that 18 is the age for marriage:


Pirkei Avot 5:21

At five [one begins the study of] the Bible.

At ten the Mishnah. At thirteen [one takes on] the [responsibility for] the mitzvot.

At fifteen [one begins the study of] the Talmud.

At eighteen [one is ready for] marriage.

At twenty to pursue [a livelihood].

At thirty [one attains full] strength.

At forty [one gains] understanding.

At fifty [one gives] counsel.

At sixty [one reaches] old age.

At seventy [one reaches] the fullness of age.

At eighty [one reaches] strong old age.

At ninety [one is] bent.

And at one hundred, it is as if one had already died and passed from the world”.


Thus at eighteen we are ready to marry and beget life.


* * *


18 laws of treife were taught to Moshe


Lag BaOmer is the 18th of Iyar.


Shabbat candles are lit and a blessing is recited no later than eighteen minutes before sunset.


An old tradition maintains that in every generation, there are thirty-six hidden righteous people (two times eighteen) for whom the world continues.


Zevachim 88b Our Rabbis taught: The robe [me’il] was entirely of blue, as it is said, And he made the robe of the ephod of woven work, all of blue. How were its skirts [made]? Blue [wool], purple wool and crimson thread, twisted together, were brought, and manufactured into the shape of pomegranates whose mouths were not yet opened and in the shape of the cones of the helmets on children’s heads. Seventy two bells containing seventy two clappers were brought and hung thereon, thirty six on each side. R. Dosa said on the authority of Rabbi Judah: There were thirty six, eighteen on each side.


King Solomon and the Messiah.


The involvement with the nations of the world, their wisdom and their art, requires extreme caution. King Solomon’s desire or “passion”[5] to rectify worldly art and science—his attraction to the culture and aesthetic of the nations—so overtook that it adversely affected his devoted obedience to the law of the Torah. The Torah permits a king to marry eighteen wives; in attempt to elevate all of the beauty and wisdom unrectified of the nations (embodied in the princess of each nation) King Solomon married a thousand wives: “King Solomon loved many foreign women, and he had many wives, that numbered seven hundred, and three hundred concubines.[6]


Sanhedrin 21a Whence do we deduce the number eighteen? — From the verse, And unto David were sons born in Hebron; and his first-born was Ammon of Ahinoam the Jezreelitess; the second, Chileab of Abigail the wife of Nabal the Carmelite; the third Absalom the son of Maacah; and the fourth, Adonijah the son of Haggith; and the fifth, Shefatiah the son of Abital; and the sixth, Ithream of Eglah, David’s wife. These were born to David in Hebron. And of them the Prophet said: And if that were too little, then would I add unto thee the like of these, [Ka-hennah] and the like of these, [we-kahennah], each ‘kahennah’ implying six, which, with the original six, makes eighteen in all.


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V. I. S. Zuri, op. cit., Part I, Bk. 3, pp. 19-27 on the significance of numbers. He maintains that eighteen is often used symbolically to denote a large number.


A Sabbath day’s journey is two thousand cubits. This is generally regarded as an eighteen minutes’ walk.


Rosh HaShana 18a The Rabbis taught: There was a family in Jerusalem the members of which used to die at the age of eighteen. They came and told Rabban Johanan b. Zaccai. He said to them, Perhaps you are of the family of Eli, to whom it was said, and all the increase of thy house shall die young men. Go and study the Torah and you may live. They went and studied the Torah and lived, and they used to call that family the family of Rabban Johanan after his name.


Rosh HaShana 20b R. Zera said in the name of R. Nahman: The moon is invisible for twenty-four hours [round about new moon]. For us [in Babylon] six of these belong to the old moon and eighteen to the new; for them [in Palestine] six to the new and eighteen to the old. What is the practical value of this remark? — R. Ashi said: To confute the witnesses.


Yoma 9a ‘The fear of the Lord prolongeth days’ refers to the first Sanctuary, which remained standing for four hundred and ten years and in which there served only eighteen high priests. ‘But the years of the wicked shall be shortened’ refers to the second Sanctuary, which abided for four hundred and twenty years and at which more than three hundred [high] priests served . Take off therefrom the forty years which Simeon the Righteous served, eighty years which Johanan the high priest served, ten, which Ishmael b. Fabi served, or, as some say, the eleven years of R. Eleazar b. Harsum. Count [the number of high priests] from then on and you will find that none of them completed his year [in office].


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This study was written by

Rabbi Dr. Hillel ben David

(Greg Killian).

Comments may be submitted to:


Rabbi Dr. Greg Killian

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[1] Berachot 28b

[2] Yerushalmi Tractate Berachot 4:3

[3] M. Kornfeld

[4] commentary on Exodus 40: 33

[5] 1 Kings 9:1

[6] ibid. 11:1-3