Ahitub in Fausset's Bible Dictionary
1. Ahimelech or Ahijah, whose father he was. (See AHIMELECH;
2. Amariah's son, and Zadok the high priest's father,
or rather grandfather (1 Chronicles 6:7-8; 2 Samuel 8:17).
Called "ruler of the house of God," i.e. high priest, 1
Chronicles 9:11. In Nehemiah 11:11 Ahitub appears as
grandfather of Zadok and father of Meraioth, of the house of
Eleazar. Thus there would seem to have been in the same age
Ahitub of the house of Eli, sprung from Ithamar, and also
Ahitub of the house of Eleazar.
3. The mention of a third Ahitub, son of another
Amariah, and father of another Zadok (1 Chronicles 6:11-12),
may be a copyist's error.