Albert Barnes' Notes on the Whole Bible - Acts 10:28
It is an unlawful thing - This was not explicitly enjoined by Moses, but it seemed to be implied in his institutions, and was, at any rate, the common understanding of the Jews. The design was to keep them a separate people. To do this, Moses forbade alliances by contract, or marriage, with the surrounding nations, which were idolatrous. See Leviticus 18:24-30; Deuteronomy 7:3-12; compare Ezra 9:11-12. This command the Jews perverted, and explained it as referring to contact of all kinds, even... read more
The Pulpit Commentary - Acts 10:28
Ye yourselves for ye, A.V.; to join himself for to keep company, A.V.; and yet unto me hath God showed for but God hath showed me, A.V. Ye yourselves know . It was notorious among the Romans that the Jews kept themselves aloof from other people. Hence the accusation against them, in common with Christians, of being haters of the human race. Tacitus says of them that they hated all people, except their own countrymen, as their enemies, and refused to eat or intermarry with them... read more