When David came to the summit where people used to worship God, Hushai from Erek met him. Hushai's clothes were ripped, and dirt was on his head.
References for 2 Samuel 15:32
David said to him, "If you come with me, you will be a burden to me.
But if you return to the city and say to Absalom, ‘King, I am your servant! Please spare my life! I was your father's servant in the past, but now I am your servant,' then you can help me by countering Ahithophel's advice.
References for 2 Samuel 15:34
The priests Zadok and Abiathar will be with you there. So report everything you hear in the king's palace to the priests Zadok and Abiathar.
Their two sons, Zadok's son Ahimaaz and Abiathar's son Jonathan, are also there. Use them to report to me everything you hear."
So David's friend Hushai went into Jerusalem, just as Absalom was entering the city.