1 Chronicles 27:33

And Absalom sent for Ahithophel the Gilonite, David’s counsellor, from his city, even from Giloh, while he offered sacrifices. And the conspiracy was strong; for the people increased continually with ...

So Hushai David’s friend came into the city, and Absalom came into Jerusalem.

And it came to pass, that when David was come to the top of the mount, where he worshipped God, behold, Hushai the Archite came to meet him with his coat rent, and earth upon his head:

Awake, O sword, against my shepherd, and against the man that is my fellow, saith the LORD of hosts: smite the shepherd, and the sheep shall be scattered: and I will turn mine hand upon the little one...

But it was thou, a man mine equal, my guide, and mine acquaintance.

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 ...

And the counsel of Ahithophel, which he counselled in those days, was as if a man had enquired at the oracle of God: so was all the counsel of Ahithophel both with David and with Absalom.