Adam Clarke on Acts 10:28

Ye know how that it is an unlawful thing, etc. - He addressed the whole company, among whom, it appears, there were persons well acquainted with Jewish customs; probably some of them were Jewish proselytes.

But God hath showed me, etc. - He now began to understand the import of the vision which he saw at Joppa. A Gentile is not to be avoided because he is a Gentile; God is now taking down the partition wall which separated them from the Jews.