Exodus 18:11

Now I know that the LORD is greater than all gods: for in the thing wherein they dealt proudly he was above them.

Jethro spoke these words when he visited Moses in the wilderness, bringing back to him Moses' wife and children, whom Moses had sent back to him before leaving Egypt. Moses went out to meet him with deference and greeting, and then recounted all the Lord had done to Pharaoh and to the Egyptians for Israel's sake, with all the hardship on the way and how the Lord had delivered them. On hearing this account, Jethro rejoiced over all the goodness shown to Israel in rescue from the hand of the Egyptians and from the hand of Pharaoh, and blessed the Lord for that deliverance.

The declaration means that in the very matter in which the Egyptians acted proudly in oppression, the Lord proved Himself above them by overcoming them and delivering His people, thereby showing He is greater than every god. The confession was followed by Jethro presenting a burnt offering and sacrifices to God and sharing bread before God with Aaron and all the elders of Israel as a feast commemorating divine mercy. The speaker was a man from the Gentile world whose acknowledgment of the Lord's greatness made him an appointed witness revealing heaven's principles.