Charles Ellicott Commentary Exodus 18:10-11

"And Jethro said, Blessed be Jehovah, who hath delivered you out of the hand of the Egyptians, and out of the hand of Pharaoh; who hath delivered the people from under the hand of the Egyptians. Now I know that Jehovah is greater than all gods; yea, in the thing wherein they dealt proudly against them." — Exodus 18:10-11 (ASV)

Jethro said, Blessed be the Lord. —Hebrew, Jehovah. The Midianites, descendants of Abraham by Keturah, acknowledged the true God, and the Israelites could rightfully join with them in acts of worship.

But it is scarcely likely that they knew God among themselves as “Jehovah.” Jethro, however, understanding Moses to speak of the supreme God under that designation, adopted it from him, blessed His name, and expressed his conviction that Jehovah was exalted above all other gods.

The pure monotheism of later times scarcely existed yet. The gods of the nations were supposed to be spiritual beings, really existent, and possessing considerable power, though very far from omnipotent. (See Deuteronomy 32:16-17.)