2 Samuel 16:20-23

20And Absalom said to Ahithophel, Give counsel among you what we shall do. 21And Ahithophel said to Absalom, Go in to thy father's concubines, whom he has left to keep the house; and all Israel shall hear that thou art become odious with thy father; and the hands of all that are with thee shall be strong. 22So they spread a tent for Absalom upon the roof; and Absalom went in to his father's concubines in the sight of all Israel. 23And the counsel of Ahithophel, which he counselled in those days, was as if a man had inquired of the word of 1God: so was all the counsel of Ahithophel both with David and with Absalom.