The “suffering servant” chapter in Isaiah was the most theologically sensitive biblical passage for Jews in Christian Europe. Rashi strikingly understands the servant as the Jewish people whose suffering atones for the sins of the nations of the world. A common understanding of his motive is his search for an explanation of Jewish tribulations during the First Crusade. Such an explanation, however, would be psychologically unsatisfying, and the possibility that Rashi was motivated primarily by considerations of pshat is greatly enhanced by indirect but compelling evidence that other medieval Jews who disagreed with him provided interpretations that reveal--against their will--that their own deepest instinct pointed to his understanding as the straightforward meaning of the passage. 

Yemei Iyun be-Tanakh