“These are the generations of Jacob, Joseph was 17...”
The first letters of this phrase are “ati yavesh” (אתי יבש), and the word yavesh (יבש), which means “dried-up” tells us that through the selling of Joseph, the upper stream of spirituality was destroyed and dried-up. That Joseph was 17 – a precise age which we don't need, since he is called “young lad” immediately after, is teaching us something else: the gematria of 17 is tov (טוב), or good. Joseph was that Righteous about whom the psalms say “Tell (call) the righteous that (he) is good.”
All generations, physical as well as spiritual, are created with the help of the Foundation. By stealing and selling Joseph, the brothers created a blemish in the upper spiritual Foundation. Joseph continued the spiritual stream of Jacob, and by being Righteous and by representing the Sefirah of Yesod (Foundation), he was in some sense their father, not brother. What the brothers ruined was the multicolored coat, or “ketonet pasim”. “Pasim” are the first letters of the phase “pitchon sigron yosef moshe” (opening, closing, Joseph, Moses), which is another name of the angel Metatron, and through the connection to the soul of Adam, Joseph and Metatron are one and the same.
Art: Diego Rodriguez de Silva y Velazquez - Joseph's Bloody Coat Brought To Jacob