Exodus 18:12

(12) Jethro . . . took a burnt offering and sacrifices for God.—Jethro had brought sacrifices with him, and now offered them in token of his thankfulness for God’s mercies towards himself and towards his kinsman. He occupied a position similar to that of Melchizedek (Genesis 14:18), holding a priesthood of the most primitive character, probably as patriarch of his tribe, its head by right of primogeniture. As Abraham acknowledged rightly the priesthood of Melchizedek (Genesis 14:19; Hebrews 7:2-9), so Moses and Aaron rightly acknowledged that of Jethro. They markedly indicated their acceptance of his priestly character by participation in the sacrificial meal, which, as a matter of course, followed his sacrifice. They “ate bread with Moses’ father in law” (or rather, brother-in-law) “before God.”