2 Samuel 15:36 (KJV)

But if thou return to the city, and say unto Absalom, I will be thy servant, O king; as I have been thy father’s servant hitherto, so will I now also be thy servant: then mayest thou for me defeat the counsel of Ahithophel.

And hast thou not there with thee Zadok and Abiathar the priests? therefore it shall be, that what thing soever thou shalt hear out of the king’s house, thou shalt tell it to Zadok and Abiathar the priests.

Behold, they have there with them their two sons, Ahimaaz Zadok’s son, and Jonathan Abiathar’s son; and by them ye shall send unto me every thing that ye can hear.

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