Joseph's blessing is the longest Jacob delivers, and Targum Pseudo-Jonathan packs it with detail no translator could resist. "Joseph, my son, thou hast become great and mighty... because thou didst subdue thy inclination in the matter of thy mistress, and in the work of thy brethren" (Genesis 49:22).
Two tests shaped Joseph. The first was Potiphar's wife, who pursued him day after day until he fled her grip, leaving his cloak behind (Genesis 39:12). The Targum calls her "thy mistress" — the wife of the master who had trusted him. The temptation was not only desire; it was convenience, safety, career. Joseph walked straight through that door and into prison rather than betray that trust.
The second test was his brothers. When famine drove them to Egypt and they knelt before him without recognizing him, Joseph held the entire arc of their sin in his hand. He could have destroyed them. He chose reconciliation (Genesis 45:4-5).
Then the Targum adds a breathtaking scene. As Joseph rode through Egyptian streets in his viceroy's chariot, "the daughters of princes walking on the high places cast before thee bracelets and chains of gold, that thou shouldst lift up thine eyes upon them." Joseph kept his eyes down. The man who had already refused one woman's embrace would not trade his soul for a hundred. Jacob blesses him, on the deathbed, for the discipline of downcast eyes.