(Exodus 18:1) "the Cohein of Midian": R. Yehoshua says: He was a priest, as in (Judges 18:30) "And Jonathan the son of Gershom the son of Menasheh — he and his sons — were Cohanim (for idolatry) to the tribe of Dan until the day the land was exiled." R. Elazar Hamodai says: He (Yithro) was an officer, as in (II Samuel 8:18) "And the sons of David were Cohanim."