Ayin is one of seven Hebrew letters, recalled by the mnemonic shatnez getz, that Jewish law requires a sofer to crown with three small decorative strokes called tagin whenever it is written in a Torah scroll, tefillin or mezuzah, a rule recorded in the Talmud at Menachot 29b. Ayin also carries a specific scribal enlargement of its own: the opening word of the Shema, shema, hear, traditionally ends in an enlarged Ayin, paired with the enlarged final Dalet that closes the prayer's declaration of God's oneness in the word echad, one, discussed elsewhere in this atlas.
Read together across the two verses, the two enlarged letters spell out the word ed, witness, and commentators have long read the pairing as meaning that reciting the Shema attentively is itself an act of bearing witness to the divine unity the prayer proclaims, one of the best-known examples of meaning drawn from enlarged Masoretic letters rather than from the ordinary text. Ayin's literal meaning, eye, is already fixed in the older palaeo-Hebrew script that Jewish tradition holds the current square alphabet replaced after the Babylonian exile, a transition covered elsewhere in this atlas, in the earliest surviving inscriptions of which the letter was drawn as a simple circle, much like the Greek and Latin letters descended from the same Phoenician ancestor, discussed elsewhere in this atlas under omicron and O.