פירוש על דברים 23:8

לא תתעב אדמי THOU SHALT NOT ABHOR AN EDOMITE utterly, although it would be proper for you to abhor him because he came out against thee with the sword (Numbers 20:18—20).

לא תתעב אדומי, “Do not abhor the Edomite.” The Torah implies that though we would have reason to abhor this people seeing that they assumed a threatening posture against us (Numbers 20,18) nonetheless we are not to hold this against subsequent generations of Edomites. seeing there is a blood bond between our two nations, both being descendants of our patriarch Yitzchak. Neither must we detest the Egyptians although they drowned our boy babies; the fact remains that at a crucial point in our history Egypt offered a home to our people at a time when Yaakov’s family was in reduced circumstances (compare Rashi). Seeing that each of these nations had been guilty of grievous sins against the Jewish people only the third generation (after the Exodus) of these people are potential candidates for conversion to Judaism. By that time they may have become more refined. We are to detest Ammon and Moav, by contrast, seeing they seduced the Jewish people into sin, The Torah goes out of its way to prohibit us from seeking the welfare of these nations.
These verses gave rise to our sage in Sifri 252 to rule that seducing someone into sin is a more grievous sin that killing him seeing that the murderer robs the victim only of life on this terrestrial sphere whereas the seducer robs him of his eternity.

Completely, etc. Rashi is answering the question: It is written afterwards, “Children who will be born to them, in the third generation, will enter.” This implies that the second generation may not enter and if so he is despised! Why then does it say in the beginning, “Do not despise”? Rashi explains that when it is written, “Do not despise,” it means do not despise completely, but you may despise a bit.