Rashi on Exodus 6:16/רש"י על שמות ו׳:ט״ז

1ושני חיי לוי וגו׳ AND THE YEARS OF THE LIFE OF LEVI WERE etc. — Why is the number of the years of Levi mentioned? In order to tell us how long the period of slavery lasted — because so long as even one of the sons of Jacob (lit. the tribes) remained alive there was no slavery imposed upon the Israelites, as it is said, (Exodus 1:6) “And Joseph died and all his brethren”, and afterwards it is stated (Exodus 1:8), “Now there arose a king” (who enslaved them); and Levi lived the longest of all of them (Seder Olam 3).