פירוש על עבודה זרה 72:3

This statement treats all of these decrees as ultimately being attempts to prevent Jews from engaging in idolatry. We should emphasize that these prohibitions against assimilation are not racial. It does not seem to be some sort of “racial purity” issue that is being discussed here. Rather, it is an issue of religious belief and practice. Living with other people, eating with them, sleeping with them, marrying them and then raising families together will inevitably lead to cultural assimilation. In this case, it will lead to Jews worshiping idols. It is this the rabbis wanted to stop. Therefore, they were accepting of conversion. The end of the statement refers twice to “another matter.” The Talmud will clarify this more below.