Acts 15:21

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.

For Moses - The meaning of this verse is, that the Law of Moses, prohibiting these things, was read in the synagogues constantly. As these commands wore constantly read, and as the Jewish converts would not soon learn that their ceremonial law had ceased to be binding, it was deemed to be a matter of expediency that no needless offence should be given to them. For the sake of peace, it was better that they should abstain from meat offered to idols than to give offence to the Jewish converts. Compare 1 Corinthians 8:10-13.Of old time - Greek: from ancient generations. It is an established custom, and therefore his laws are well known, and have, in their view, not only the authority of revelation, but the venerableness of antiquity.

In every city - Where there were Jews. This was the case in all the cities to which the discussion here had reference.

Them that preach him - That is, by reading the Law of Moses. But, in addition to reading the Law, it was customary also to offer an explanation of its meaning. See the notes on Luke 4:16-22.

15:21 Perhaps the connection is, To the Jews we need write nothing on these heads; for they hear the law continually.