Charles Spurgeon Commentary Acts 13:23-25

"Of this man`s seed hath God according to promise brought unto Israel a Saviour, Jesus; when John had first preached before his coming the baptism of repentance to all the people of Israel. And as John was fulfilling his course, he said, What suppose ye that I am? I am not [he]. But behold, there cometh one after me the shoes of whose feet I am not worthy to unloose." — Acts 13:23-25 (ASV)

Of this man's seed hath God according to his promise raised unto Israel a Saviour, Jesus: When John had first preached before his coming the baptism of repentance to all the people of Israel. And as John fulfilled his course, he said, Whom think ye that I am? I am not he. But, behold, there cometh one after me, whose shoes of his feet I am not worthy to loose.

He brings in the testimony of John, who was universally respected among them. They regarded him as the last of the prophets, and so Paul tries to win their kind feelings.