Various numbers play a significant role in Jewish texts or practice. Some such numbers were used as mnemonics to help remember concepts, while other numbers were considered to have intrinsic significance or allusive meaning.
The song Echad Mi Yodea ("who knows one?"), sung at the Passover Seder, is known for recounting a religious concept or practice associated with each of the first 13 numbers.
In Jewish History
In Jewish historical study, numbers were believed to be a means for understanding the divine. This marriage between the symbolic and the physical found its pinnacle in the creation of the Tabernacle. The numerical dimensions of the temple are a "microcosm of creation ... that God used to create the Olamot-Universes."
In the thought system of Maharal, each number has a consistent philosophical meaning: 1 - unity. 2 - dualism and multiplicity. 3 - the unity between two extremes. 4 - multiplicity in two directions, like the cardinal directions. 5 - the center point which unifies those four extremes. 6 - multiplicity in three dimensions. 7 - the center point which unifies all of nature, as with Shabbat. 8 - the supernatural realm which feeds nature, and the striving of man for a connection with the supernatural. 9 - the most complete multiplicity, including division between the natural and supernatural. 10 - the final unification between natural and supernatural.
1
One is our God, in heaven and on earth - אחד אלוהינו שבשמיים ובארץ
2
Two are the tablets of the covenant - שני לוחות הברית
There are two inclinations - good (yetzer hatov) and bad (yetzer hara)
3
Three are the Fathers (Patriarchs) - שלושה אבות (Abraham, Isaac and Jacob) The three sons of Noah (Ham, Shem and Japheth) Number of aliyot on a non-Yom Tov Monday and Thursday Torah reading and number of aliyot in Shabbat Mincha The Holy of Holies occupied one-third of the area of the Temple (and previously, Tabernacle) The angels declared that God was "Holy, holy, holy" for a total of three times The Priestly Blessing contains three sections On the third day the Jewish people received the torah
4
Four are the Mothers (Matriarchs) - ארבע אימהות (Sarah, Rebecca, Rachel, and Leah) The number of aliyot on Rosh Chodesh At the Passover Seder four cups of wine are drunk, and four expressions of redemption are recited Both the heavens and earth were described as having four sides or corners, similar to the cardinal directions.
5
Five are the books of the Torah - חמישה חומשי תורה
Of the Ten Commandments, five were written on each of the two tablets. The sections of the book of Psalms The number of knots in the tzitzit Number of aliyot on Yom Tov that does not coincide with Shabbat Five species of grain
6
Six are the books of the Mishnah - שישה סידרי משנה
The six working days of the week
The six days of Creation
7
According to a midrash, "All sevens are beloved": There are seven terms for the heavens and seven terms for the earth; Enoch was the seventh generation from Adam; Moses was the seventh generation from Abraham; David was the seventh son in his family; Asa (who called out to God) was the seventh generation of Israelite kings; the seventh day (Shabbat), month (Tishrei), year (shmita) and shmita (jubilee) all have special religious status. The Seven Laws of Noah The counting of the Omer consists of seven weeks, each of seven days Number of blessings in the Sheva Brachot A woman in niddah following menstruation must count seven "clean days" prior to immersion in the mikvah Acts of atonement and purification were accompanied by a sevenfold sprinkling The menorah in the Temple had seven lamps The shiva mourning period is seven days Number of days of Sukkot and Pesach (Israel) Number of blessings in the Amidah of Shabbat, Yom Tov, and all Musaf prayers (except Rosh Hashanah) Number of aliyot on Shabbat There were seven of every pure animal in Noah's Ark The number seven is said to symbolize completion, association with God, or the covenant of holiness and sanctification Moses died on the seventh of Adar Number of days in the weekly cycle including counting of the Sabbath
8
Eight are the days of the circumcision - שמונה ימי מילה
Total number of days of Yom Tov in a year in Israel
Number of days of Chanukah
8 days of sukkos
Number of days of Pesach (Diaspora) According to the Zohar, the number eight signifies new beginnings because the eighth day was the first day after creation when God returned to work; the week began again.