John Calvin Commentary Acts 15:32

"And Judas and Silas, being themselves also prophets, exhorted the brethren with many words, and confirmed them." — Acts 15:32 (ASV)

Judas and Silas. These two brothers were sent for this reason: that they might also testify by word to what was contained in the letters, and even more. Otherwise, the apostles would not have sent such short letters concerning such a great and weighty matter. They would also have spoken something about the mysteries of faith and would have made a long exhortation, in which they would have persuaded them to the study of godliness.

Now, Luke shows some further things they did; namely, that being equipped with the gift of prophecy, they generally edify the Church. It is as if to say, they not only did their duty faithfully in the matter at hand, but they also took good and profitable pains in teaching and exhorting the Church. And we must note that he says they exhorted the Church because they were prophets, for it is not common for all people to enter such an excellent office.

Therefore, we must beware lest anyone exceed his limits, as Paul teaches (1 Corinthians 7:20 and Ephesians 4:1) that everyone should keep himself within the measure of grace he has received. For this reason, it is not in vain that Luke says the office of teaching is special, lest anyone—through ambition, lacking ability, or through rash zeal, or any other foolish desire to thrust himself forward—disturb the order of the Church.

They were prophets. While the word has diverse meanings, it is not used here for those prophets who were granted the ability to foretell future events, because this title would be out of place when he is discussing another matter. Instead, Luke’s meaning is that Judas and Silas were endowed with excellent knowledge and understanding of God’s mysteries, so that they might be good interpreters of God. As Paul, in 1 Corinthians 14:3, when he discusses prophecy and prefers it above all other gifts, does not speak of foretelling future events, but he commends it for this fruit: because it edifies the Church by doctrine, exhortation, and consolation. In this way, Luke assigns exhortation to the prophets as the principal point of their office.