Hebrews 8:4 - Ellicott's Commentary On The Whole Bible

For if he were... — The oldest Greek MSS. and two important versions read, “If then He were”; and two other changes in the text of this verse also rest on high authority. In its correct form the verse will stand thus: If then He were on earth, He would not even be a priest (that is, He would not be a priest at all), seeing there are those who according to law offer the gifts. The argument somewhat resembles that of Hebrews 7:13-14; there, however, the impediment is that of tribe; here the thought is that the place is preoccupied by men who by express command are bringing the gifts unto God.