The comments and midrashim that Rashi brings not because of any interpretative need, nor because of their educational or moral significance, but rather because of their exigency for his generation, a generation living beneath the shield and the sword of the Christian faith are examined.
Rashi sometimes strays from the peshat of the verses because of the need to contend with Christian claims against the Jews, out of his desire to strengthen the spirit of his nation.
There is no doubt that Rashi, in his commentary to Shir Ha-shirim, is responding to the First Crusade. Similarly, in his commentaries to a number of psalms and the Book of Yeshayahu, Rashi relates to the cruelty of the Christians, their claims against the nation of Israel, and the punishment that God is destined to bring upon them.
Also in the Torah itself, we find anti-Christian trends in Rashi's commentary.
