2 Samuel 17:18

17:18 But a young man saw them on one occasion and informed Absalom. So the two of them quickly departed and went to the house of a man in Bahurim. There was a well in his courtyard, and they got down in it.

2 Samuel 16:23

16:23 In those days Ahithophel’s advice was considered as valuable as a prophetic revelation. Both David and Absalom highly regarded the advice of Ahithophel.