And the king said unto him, Go in peace. So he arose, and went to Hebron.

Wesley's Notes

15:9 Hebron - This place he chose as being an eminent city, and next to Jerusalem, the chief of the tribe of Judah, and the place where his father began his kingdom, which he took for a good omen. And where it is probable he had secured many friends. It was also at a convenient distance from Jerusalem.

Matthew Henry's Concise Commentary

15:7-12 See how willing tender parents are to believe the best concerning their children. But how easy and how wicked is it, for children to take advantage of good parents, and to deceive them with the show of religion! The principal men of Jerusalem joined Absalom's feast upon his sacrifice. Pious persons are glad to see others appear religious, and this gives occasion for deceptions. The policy of wicked men, and the subtlety of Satan, are exerted to draw good persons to countenance base designs.