John Wesley on 1 Corinthians 9:20

To the Jews I became as a Jew - Conforming myself in all things to their manner of thinking and living, so far as; I could with innocence. To them that are under the law - Who apprehend themselves to be still bound by the Mosaic law. As under the law - Observing it myself, while I am among them. Not that he declared this to be necessary, or refused to converse with those who did not observe it. This was the very thing which he condemned in St. Peter, Gal 2:14.