Tav is the twenty second, letter of the Hebrew alphabet.

The gematria of Tav is 400.

The numerical value of tav is four hundred. We find the num­ber four hundred mentioned frequently in the Torah. One instance is when Abraham needed to buy a burial place for his wife, Sarah. The Torah tells us that he went to Ephron, the leader of the Hittite people, in the city of Hebron and asked him for a piece of land. Ephron responded that he would sell the parcel for four hundred shekels. The name Ephron, עפרן,has the gematria of 400: ayin = 70, pei = 80, reish = 200, and nun = 50. Significantly, Hebron was the first city in the land of Israel to be officially purchased by the Jewish people.

Furthermore, the letter tav in the “small gematria,” is four. The cave where Sarah was buried is called the “cave of the four couples,” as Adam and Chava (Eve), Abraham and Sarah, Isaac and Rebecca, and Jacob and Leah are all buried there.

Four hundred also represents the four hundred worlds of pleas­ure that the righteous people will acquire in the World to Come. The Land of Israel, according to the dimensions in the Torah, measures 400 by 400 mil (a mil is approximately 1 kilometer).

The number four hundred is also found pertaining to the “Covenant between the Parts,”. When G‑d caused Abraham to fall into a deep slumber and told him that his children would reside in a foreign land (the land of Egypt) for four hundred years and afterwards go out with great wealth and an out­stretched arm.

Yet another instance of four hundred is found in the account of Jacob’s encounter with his brother Esau after sojourning twenty years in the house of Laban. When Jacob approaches Esau he is informed that Esau is mighty, for he has with him four hundred men. As a result, Jacob sends forth a messenger to tell Esau, “I sojourned (garti) in Laban’s house for twenty years. ”The word garti, גרתי, (“sojourned”) has the gematria of 613, and is synonymous with the 613 commandments. What Jacob thus communicated to his brother was, “Though I lived in the house of this wicked Laban, I did not violate any of the 613 commandments.” The word garti can also mean to live as a foreigner. When it came to Jacob’s physical existence, the materialistic aspects of life, he lived as a foreigner, meaning that he recognized materialism and physicality as merely the means to serve G‑d, not as an end in themselves. This gave him the strength to keep the whole Torah. Twenty times twenty equals four hundred. Therefore after his twenty years of refine­ment, Jacob now possessed the ability to overcome the four hundred men of Esau.

Finally, the numerical value of tav can represent both the four hundred levels of evil and the four hundred sparks of G‑dliness that are found in the world. The tav thus embodies the ability to transform these negative energies into positive sparks.