What first gave rise to the hypothesis [of Yahweh's Midianite origin] in the first place was a historical-critical interpretation of those biblical texts which narrate how Moses, son of Levitical parents (Exod. 2.1-2), married a Midianite woman, and lived long enough in Midian to have two sons with her (Exod. 2.11-22).

During this time he was in service with his father-in-law, a priest (perhaps the priest) of Midian, named both Reuel (Exod. 2.18) and Jethro (Exod. 2.1; 4.18).

At a sacred spot, a 'mountain of God', situated beyond the normal pasturage of the Midianites but frequented by Midianites and no doubt other tribes, Moses received a revelation from a deity previously known to him only notionally if at all (Exod. 3.13), presumably a deity worshipped by Midianites, whose named was revealed to be Yahweh.

(pp. 133-134)

(from 'The Midianite-Kenite Hypothesis Revisited and the Origins of Judah', JSOT 33.2 (2008): 131-153)

Joseph Blenkinsopp