Judas and Silas, being prophets themselves - that is, inspired teachers.
exhorted the brethren with many words - “much discourse.”
and confirmed them - opening up, no doubt, the great principle involved in the controversy now settled, of gratuitous salvation, or the purification of the heart by faith alone (as expressed by Peter, Act 15:9, Act 15:11), and dwelling on the necessity of harmony in principle and affection between the Gentile disciples and their Jewish brethren.