Or HaChaim on Genesis 49:22/אור החיים על בראשית מ״ט:כ״ב

1 בן פורת יוסף, בן פורת עלי עין, "Joseph is a fruiful son, fruitful to the eye, etc." The reason Jacob repeated the word פורת, fruitful, may have to do with Joseph's fertility being twofold We have already explained (Sotah 36) that Joseph had originally been intended to father twelve tribes; the second reason was that he resisted the temptation to sleep with Potiphar's wife, i.e. עלי עין, he overcame the temptation to follow his eyes, proved superior to visual allure.

2Jacob continued with בנות צעדה. According to Tanchuma the wife of Potiphar called all the wives of the Egyptian elite and had Joseph perform personal valet services for them. Being surrounded by all these ladies was equivalent to this אצעדה, bracelet, Jacob describes here. עלי שור, the point of the exercise was to ogle Joseph. The Torah testifies that in spite of all this Joseph refrained from looking at all these provocative women. Seeing that Joseph did not make improper use of his eyesight he and his descendants in turn were rewarded by remaining immune to the evil eye.