Original Verse:
Ezra Chapter 7 Verse 2The son of Shallum, the son of Zadok, the son of Ahitub,

Reference Verses:
2nd Samuel Chapter 8 Verse 17And Zadok the son of Ahitub, and Ahimelech the son of Abiathar, were the priests; and Seraiah was the scribe;
1st Kings Chapter 2 Verse 35And the king put Benaiah the son of Jehoiada in his room over the host: and Zadok the priest did the king put in the room of Abiathar.