2 Samuel 17:2-4
17:2 When I catch up with him he will be exhausted and worn out. I will rout him, and the entire army that is with him will flee. I will kill only the king
17:3 and will bring the entire army back to you. In exchange for the life of the man you are seeking, you will get back everyone. The entire army will return unharmed.”
17:4 This seemed like a good idea to Absalom and to all the leaders of Israel.
2 Samuel 17:23
17:23 When Ahithophel realized that his advice had not been followed, he saddled his donkey and returned to his house in his hometown. After setting his household in order, he hanged himself. So he died and was buried in the grave of his father.