2 Samuel 16:20-23

Then Absalom said to Ahithophel, “Give me your advice. What should we do?” Ahithophel said to Absalom, “Go in to your father’s concubines, whom he has left behind to take care of the house; then all Israel will hear that you have made yourself odious to your father. Then the hands of all who are with you will be strengthened [by your boldness and audacity].” So they pitched a tent for Absalom on the roof [of the king’s palace], and Absalom went in to his father’s concubines in the sight of all Israel. [2 Sam 12:11, 12] The advice of Ahithophel, which he gave in those days, was as if a man had consulted the word of God; that is how all Ahithophel’s counsel was regarded by both David and Absalom.