Acts 15:21 - Ellicott's Commentary On The Whole Bible

For Moses of old time. — Literally, of ancient generations. The conjunction gives the reason for writing to the Gentiles, and giving them these injunctions. The Jews, who heard the Law in their synagogues every Sabbath, did not need instruction. It might be taken for granted that they would adhere to the rules now specified. So, in Acts 15:23, the encyclical letter is addressed exclusively to “the brethren of the Gentiles.”