Jamieson, Fausset and Brown on Job 42:8

8. seven--(See Introduction). The number offered by the Gentile prophet (Nu 23:1). Job plainly lived before the legal priesthood, &c. The patriarchs acted as priests for their families; and sometimes as praying mediators (Ge 20:17), thus foreshadowing the true Mediator (1Ti 2:5), but sacrifice accompanies and is the groundwork on which the mediation rests.

him--rather, "His person [face] only" (see on Job 22:30). The "person," must be first accepted, before God can accept his offering and work (Ge 4:4); that can be only through Jesus Christ.

folly--impiety (Job 1:22; 2:10).