The Hebrew system of assigning numerical values to letters of the alphabet. Each Hebrew letter corresponds to a number.

Alef is 1, bet is 2, and so forth to yod which is 10. The next letter, kaf, is 20, and so on to kof, 100. After that are raish, 200, shin 300, and tav, 400.

Orthodox Jews use gematria for Torah exegesis by finding different words with the same numeric value. For example, the Hebrew word for love is ahavahalef-hay-bet-hay, which adds up to 13.

The word for compound unity is ekhadalef-khet-dalet, which also adds up to 13. So love and unity are related. The Holy Trinity, who is one, is also pure love.

Another example is lamed vav (Hebrew: 36), a Talmudic tradition (Sanhedrin 97b, Sukkot 45b) that the world must contain at least 36 tzadikim, righteous people, for God to keep mankind in existence. They are generally humble and known for their holiness only to God.