Zayin is the seventh letter and has the value seven. Sefer Yetzirah places it among the letters of the teeth, with Samekh, Shin, Resh and Tzadi. In Torah scrolls, it is one of the seven letters the Talmud names Sha'atnez Getz, Shin, Ayin, Tet, Nun, Zayin, Gimel and Tzadi, which each carry three small crowns. The Talmud calls these crowns ziyunin; one may bring this word close to the name of the letter, though the text does not say so.
In Sefer Yetzirah, Zayin is one of the twelve simples. G-d "made the letter Zayin reign and bound a crown to it," and through it formed Te'omim, the Twins, in the world, the month of Sivan in the year and the right foot in the body. The book arranges the twelve simples on the twelve diagonal borders of space, which extend without end and are "the arms of the world."
In tractate Shabbat, after "Heh Vav, this is the Name of the Holy One, blessed be He," the children read the following letters in one stretch: "Zayin Chet Tet Yod Kaf: if you do so," that is, if you do good to the poor, "the Holy One, blessed be He, feeds you." Zayin gives zan, to feed. The first reward of the one who gives is to be fed himself.
Tractate Menachot relates, in the name of Rav, that when Moses went up on high, he found the Holy One, blessed be He, sitting and binding crowns to the letters. He asked: "Master of the world, who holds back Your hand?" G-d answered that a man would come after many generations, Akiva son of Yosef, who would derive from every stroke heaps of laws. Moses sat at the end of eight rows in Rabbi Akiva's class and did not understand what was being said; his strength failed. When a student asked Rabbi Akiva where he had a certain law from, he answered: "It is a law given to Moses at Sinai," and Moses' mind was set at ease. Finally, the Alphabet of Rabbi Akiva says of Zayin: it is the Name of the Holy One, blessed be He, who feeds, zan, all His creatures every day, from the horns of the wild oxen to the eggs of lice.
Seven, the crown and the bread. In the scroll, Zayin carries three crowns from which, says the Talmud, heaps of laws will be derived; for the children of Shabbat 104a, it announces that G-d feeds the one who gives; in Sefer Yetzirah, it forms the month of Sivan. A small letter, which the tradition crowns and from which it expects much.