acts 15:23 And they wrote letters by them after this manner; The apostles and elders and brethren send greeting unto the brethren which are of the Gentiles in Antioch and Syria and Cilicia: - Free Bible Online

      23. And they wrote . . . by them--This is the first mention in the New Testament history of writing as an element in its development. And the combination here of written and oral transmission of an important decision reminds us of the first occasion of writing mentioned in the Old Testament, where a similar combination occurs (Ex 17:14). But whereas there it is the deep difference between Israel and the Gentiles which is proclaimed, here it is the obliteration of that difference through faith in the Lord Jesus [BAUMGARTEN].
      greeting--The only other place in the New Testament where this word occurs (except in the letter of Lysias, Ac 23:26) is Jas 1:1, which seems to show that both letters were drawn up by the same hand [BENGEL].
      the Gentiles in Antioch, and Syria, and Cilicia--showing that churches then existed in Cilicia as well as Syria, which owed their existence, in all likelihood, to Paul's labors during the interval between his return to Tarsus (Ac 9:30) and his departure in company with Barnabas for Antioch (see on Ac 11:25).

JFB.