2 Samuel 15:9

7At the end of forty years, Absalom said to the king, “Please let me go and pay my vow, which I have vowed to the LORD, in Hebron.

8For your servant vowed a vow while I stayed at Geshur in Syria, saying, ‘If the LORD shall indeed bring me again to Jerusalem, then I will serve the LORD.’”

9The king said to him, “Go in peace.” So he arose and went to Hebron.

10But Absalom sent spies throughout all the tribes of Israel, saying, “As soon as you hear the sound of the trumpet, then you shall say, ‘Absalom is king in Hebron!’”

11Two hundred men went with Absalom out of Jerusalem, who were invited, and went in their simplicity; and they didn’t know anything.