Who was Hushai?
Hushai was an Archite, native of Archi, West of Bethel on the northern border of Benjamin and southern border of Joseph ( Joshua 16:2 ).
Hushai was one of David's most faithful and wise counselors. When David was fleeing from Jerusalem and Absalom, Hushai met him, having his coat rent and earth on his head. The king persuaded him to return to Jerusalem, feign submission to Absalom, and try to defeat the counsel of Ahithophel (2 Samuel 15:32 f).
Whatever Absalom decided on, Hushai was to send word to David through two young men, sons of the priests Zadok and Abiathar ( 2 Samuel 15:34-36 ). Hushai obeyed, and succeeded in persuading Absalom to adopt his counsel rather than that of Ahithophel (2 Sam 16:16-17:14). He sent word to David of the nature of Ahithophel's counsel, and the king made good his escape that night across the Jordan. The result was the suicide of Ahithophel and the ultimate defeat and death of Absalom.
IBSE, "Absalom" (in the public domain) with minor edits.