The Coat of Many Colors? Genesis 37:3

Israel loved Yosef...R Y'hudah and R Nechemiah. R Y'hudah said: the brightness of features was his, similar to him. (i.e. זקנים is to be seen as a combination of זיו and איקונין) R Nechemiah said: all the halachot Shem and Ever had passed to Ya'akov, he passed to him. And he made for him a k'tonet passim. Resh Lakish, in the name of R Elazar benAzaria said: One should not treat one of his sons differently, for because of the k'tonet passim his father Ya'akov made for Yosef, they hated him. . .. פסים passim, for it reached the palm פס of his hand. Another explanation: for it was exceedingly thin and light and could be hidden in the palm of a hand. פסים, for they cast lots (פיס, post biblical Hebrew) over it for which of them would take it to his father, and selected Y'hudah. פסים on account of the troubles that overtook him: פ Potifar, ס sochrim, "traders," י Yishm'elim, מ Midyanim. Another explanation: פסים, Resh Lakish in the name of R Elazar benAzariah: "Go see the acts of God."(Psalms 66:5) And in the next verse: "He turned sea to dry land." Why did they hate him? Because the sea would be torn before them. פסים= "strip" פס of "sea" ים.

Son of old age...for he was born to him at the time of his old age, but Onkelos translated: "wise son," all that he learned from Shem and Ever he passed to him. Another explanation: his appearance was like his, similar to him.

פסים. expression for garment of fine wool, like“green wool (כַּרְפַּס) and blue” (Esther 1:6), and like the k'tonet passim of Tamar and Amnon (2 Sam. 13:18). But Midrash Agadah references his troubles, that he was sold to Potiphar , to the sochrim, to the Yishmaelim, and to the Midyanim.

For he was a son of old age. As it sounds, for he begat him when he was 91. His brother Binyamin they also called "child of old age." And after these two none were born to him. passim, embroidered tunic. Passim is like pas yada (palm of the hand) in Aramaic.

And Israel loved. . . All this caused the jealousy. son of old age -- for he was the last of 11 sons, Binyamin not being born immediately afterward but following much time. Long before Binyamin had been born Yosef had been a son of old age and Ya'akov had begun to love him. passim -- robe.

Should you say, but Binyamin was born to him further into his old age, it must be said that all the sons of Ya'akov were born to him one after the other, in six years, all but Binyamin, born after a long interval. Everyone thought that he would have no more sons from her so they called Yosef Son of old Age. And even after Binyamin was born, they called him that because they had become accustomed to it.

Because the first explanation was problematic–what difference does it make if he was born in his old age or in the days of his youth? Therefore the Onkelos reference. Being for Rashi yet problematic to say of him "son of his old age," he questions the word זקונים in order to introduce the זיו איקונין interpretation. (Maharshal)

Regarding the difficulty in "what difference does it make," the text says that he made for him a k'tonet passim. If you argue that it is to teach that a person should not treat one of the sons differently, for on account of two selas by which Yosef's tunic was more valuable his brothers became jealous of him, this is not the intention of the text. (cf T. Shab 10b) For it is not written "His brothers feared because he made for him a k'tonet passim, but surely on account of his dreams and words they became jealous of him. Therefore he brings Midrash Agadah, etc. (Maharshal) He wants to say that פסים is acrostic for Potifera, sochrim, Yishma'elim, and Midyanim. It must be said regarding this agadah, that vav is missing from the word sochrim in the verse: "Men passed, Midyanim sochrim." (v.28) It should have been v'sochrim (and merchants). Further, absent in the text is selling of Yosef to merchants, and for that matter, neither is selling to Midyanim. If it is not thus for merchants, why here?

He made for him a k'tonet passim as a sign that he would be the leader at home and in the field. Similar to "I shall dress him in your tunic"(Is 22:21). And as they, z.l., say "the greatest of the brothers, so that his words be heard (T. BK 11b)