10 Then Absalom sent undercover agents to all the tribes of Israel with the message, "When you hear the blast of the ram's horn trumpet, that's your signal: Shout, 'Absalom is king in Hebron!'" 11 Two hundred men went with Absalom from Jerusalem. But they had been called together knowing nothing of the plot and made the trip innocently. 12 While Absalom was offering sacrifices, he managed also to involve Ahithophel the Gilonite, David's advisor, calling him away from his hometown of Giloh. The conspiracy grew powerful and Absalom's supporters multiplied.

Matthew Henry's Commentary on 2 Samuel 15:10-12

Commentary on 2 Samuel 15:7-12

(Read 2 Samuel 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.