Midrasch zu Tehillim 66:6

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 of sea" פס ים.