The Oral Talmud with Benay Lappe and Dan Libenson Episode 98

Rabbi Yoḥanan was accustomed to go and sit at the gates of the immersion sites. He said: When the daughters of Israel emerge from their immersion, they will look at me, and will have children as beautiful as I. The Sages asked him: Master, do you not fear the evil eye? He said to them: I descend from the seed of Joseph over whom the evil eye has no dominion, as it is written: “Joseph is a bountiful vine, a bountiful vine on a spring [alei ayin]” (Genesis 49:22). (“Ayin” can mean both “spring” and “eye.”) And Rabbi Abbahu said a homiletic interpretation: Do not read it alei ayin, rather olei ayin (above the eye). Rabbi Yosei, son of Rabbi Ḥanina, cited a different proof, from Jacob’s blessing of Joseph’s sons, Ephraim and Menashe: “The angel who redeems me from all evil shall bless the young and in them may my name be recalled, and the name of my fathers, Abraham and Isaac, and may they multiply [veyidgu] in the midst of the earth” (Genesis 48:16). (Veyidgu is related etymologically to the word fish -- dag). Just as the fish in the sea, water covers them and the evil eye has no dominion over them, so too the seed of Joseph, the evil eye has no dominion over them. And if you wish, say instead: Joseph’s eye, which did not seek to feast on that which was not his, Potiphar’s wife -- the evil eye has no dominion over him.