Aaronites

Aaronites - the descendants of Aaron, and therefore priests. Jehoiada, the father of Benaiah, led 3,700 Aaronites as "fighting men" to the support of David at Hebron (1 Chr. 12:27). Eleazar (Num. 3:32), and at a later period Zadok (1 Chr. 27:17), was their chief.

From Easton's Bible Dictionary (1897)