Albert Barnes Commentary Acts 15:12

"And all the multitude kept silence; and they hearkened unto Barnabas and Paul rehearsing what signs and wonders God had wrought among the Gentiles through them." — Acts 15:12 (ASV)

Then all the multitude. Evidently, this refers to the multitude of private Christians who were assembled on this occasion. That it does not refer merely to a synod of ministers and elders is apparent for the following reasons:

1. because the church, the brethren, are represented as having been present and concurring in the final opinion (Acts 15:22–23); and
2. because the word "multitude" (to plēthos) would not have been used to describe merely a collection of apostles and elders (Compare to Luke 1:10-11, 13; Luke 5:6; Luke 6:17; Luke 19:37; John 5:3; John 21:6; Acts 4:32; Acts 6:2; Matthew 3:7).

Gave audience. They heard; they listened attentively.

Barnabas and Paul. They were deeply interested in it and were qualified to give a fair statement of the facts as they had occurred.

Declaring what miracles and wonders, etc. The argument here evidently is, that God had approved their work by miracles; that He gave evidence that what they did had His approbation; and that as all this was done without imposing on them the rites of the Jews, so it would follow that these rites were no longer to be commanded.

An alternative for "audience" is "hearkened to." See also God had wrought (Acts 14:27).