Because he abideth (dia to menein auton). Same idiom as in verse Philippians 23 , "because of the abiding as to him" (accusative of general reference, auton). Unchangeable (aparabaton). Predicate adjective in the accusative (feminine of compound adjective like masculine), late double compound verbal adjective in Plutarch and papyri, from alpha privative and parabainw, valid or inviolate. The same idea in verse Philippians 3 . God placed Christ in this priesthood and no one else can step into it. See verse Philippians 11 for ierwsunh.