Jamieson, Fausset and Brown on Acts 15:13

13. James answered, saying, &c.--Whoever this James was (see on Ga 1:19), he was the acknowledged head of the church at Jerusalem, and here, as president of the assembly, speaks last, winding up the debate. His decision, though given as his own judgment only, could not be of great weight with the opposing party, from his conservative reverence for all Jewish usages within the circle of Israelitish Christianity.