Acts 15:21 - Clarke's commentary and critical notes on the Bible

For Moses of old time hath in every city them that preach him, being read in the synagogues every sabbath day. Moses of old time hath in every city - The sense of this verse seems to be this: As it was necessary to write to the Gentiles what was strictly necessary to be observed by them, relative to these points, it was not so to the converted Jews; for they had Moses, that is, the law, preached to them, κατα πολιν, in the city, that is, Antioch; and, by the reading of the law in the synagogues every Sabbath day, they were kept in remembrance of those institutions which the Gentiles, who had not the law, could not know. Therefore, James thought that a letter to the converted Gentiles would be sufficient, as the converted Jews had already ample instruction on these points.