The Seforno to Bereishit 46:3, in commenting on the verse, "Fear not to go down into Egypt" writes:
If you remain here your children will intermarry and become absorbed by the Caananites, but in Egypt they will not be able to do so, 'because the Egyptians may not eat bread with the Hebrews' (Bereishit 43:32), therefore they will be a separate, distinct people, as our Sages state, "The verse, 'and he became there a nation' (Devarim 26:5) teaches us that they were distinctive there".
It seems to me this a is a powerful vindication of those who erect invisible walls of purity and a repudiation of those who laud living among the religiously tolerant.
