2 Samuel 17:14, 23

And Absalom and all the men of Israel said, The counsel of Hushai the Archite is better than the counsel of Ahithophel. For the LORD had appointed to defeat the good counsel of Ahithophel, to the intent that the LORD might bring evil upon Absalom.

And when Ahithophel saw that his counsel was not followed, he saddled his ass, and arose, and gat him home to his house, to his city, and put his household in order, and hanged himself, and died, and was buried in the sepulchre of his father.