Zadok, a direct descendant of Aaron, was one of David’s most loyal allies, even in his darkest moments.
Aside from a passing reference in the context of David’s consolidation of power ( 2 Samuel 8), Zadok first appeared in the story after David was unseated in a coup led by his own son Absalom. Zadok decided to accompany the king as he fled Jerusalem.
More important, Zadok and his fellow priests meant to take the ark of the covenant with them—a powerful sign that in their estimation, David was still the rightful king and the recipient of God’s blessing.
David wisely counseled Zadok to turn back. He knew from previous history that the ark was no magic token—but most of all, it was meant to stay in God’s chosen city, among God’s chosen people. Zadok obediently returned to Jerusalem, where he paved the way for David’s triumphant return following Absalom’s death.
Before David died, Zadok had one more opportunity to demonstrate his loyalty to Israel’s greatest king. David’s intent was for Solomon to succeed him as king. However, when Adonijah moved to preemptively install himself as David’s successor, a number of David’s advisers— including the priest Abiathar—rallied to him.
Zadok, however, stood by the dying king’s wishes. Together with the prophet Nathan, Zadok had the honor of anointing Israel’s next rightful king, Solomon. Zadok ended up replacing Abiathar as well.
Zadok’s descendants served in the temple until the destruction of Jerusalem in 586 BC. According to the prophet Ezekiel, they alone were worthy to enter God’s sanctuary, because they alone had remained pure while the rest of the Israelites strayed from God ( Ezekiel 44:15–16).