Matthew Poole and continuators on Acts 13:15

15 And after the reading of the law and the prophets, the rulers of the Synagogue sent unto them, saying, Ye men and brethren, If ye have any word of exhortation for the people , say on.

The reading of the Law was commanded by Moses; and they say, that Ezra commanded the reading of the Prophets also in their Synagogues, which was used; as we may see in the 27th Verse. And so divided into several Sections, that once a Year they might be all read over.

They were such as had the over-sight of this Service of God in their Synagogues, that it might be performed according to the prescription.

An usual compellation which the Iews gave one another, owning them to serve the same God, and professing a suitable respect for them.

After the reading before spoken of, there followed a Sermon, or Exhortation; which the Apostles are desired to make, the Rulers of the Synagogue, as 'tis supposed, having had some previous knowledg of them.