English of Core Text: Rabbi Yehoshua said: One who sees a tet in his dream — it is a good sign for him. What is the reason? ... Rather, because Scripture first opened with it for good — from “Bereishis” until “And God saw the light that it was good” no tet is written.
On the daf / in context: In a discussion of dream omens the Gemara notes that the letter tet first appears in the word “tov” of our passuk. That initial positive appearance makes the letter a favorable sign.
Type of Learning: Custom (first occurrence of letter tet)What Is Learned: The first appearance of the letter tet in the Torah is in “ki tov,” giving the letter a positive association.