2 Samuel 15:10-12

But Absalom sent spies throughout all the tribes of Israel, saying, “As soon as you hear the sound of the trumpet, you shall say, ‘Absalom is king in Hebron.’ ” Then two hundred men from Jerusalem who were invited [as guests to his sacrificial feast] went with Absalom. They went innocently and knew nothing [about his plan against David]. And Absalom sent for Ahithophel the Gilonite, David’s counselor, from his city Giloh, while he was offering sacrifices. And the conspiracy grew strong, for the people with Absalom increased continually.