2 Samuel 15:10-13

10But Absalom sent secret messengers throughout all the tribes of Israel, saying, "As soon as you hear the sound of the trumpet, then say, 'Absalom is king at Hebron!'"

11With Absalom went two hundred men from Jerusalem who were invited guests, and they went in their innocence and knew nothing.

12And while Absalom was offering the sacrifices, he sent for Ahithophel the Gilonite, David's counselor, from his city Giloh. And the conspiracy grew strong, and the people with Absalom kept increasing.

13And a messenger came to David, saying, "The hearts of the men of Israel have gone after Absalom."