2 Samuel 16:20-23

²⁰Then Absalom said to Ahithophel, “Give your advice. What should we do?” ²¹Ahithophel said to Absalom, “Have relations with 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 repulsive to your father. The hands of all who are with you will also be strengthened.” ²²So they pitched a tent for Absalom on the roof, and Absalom had relations with his father’s concubines in the sight of all Israel. ²³Now the advice of Ahithophel, which he gave in those days, was taken as though one inquired of the word of God; so was all the advice of Ahithophel regarded by both David and Absalom.