The verse records a startling act (Exodus 18:12): "Yithro, Moses' father-in-law, took a burnt-offering and peace-offerings for sacrifice to God." The Mekhilta says that Scripture deliberately "registers wonder here" — the text itself is astonished at what it is recording.
Consider who Yithro was. He was a man who had worshipped idolatry his entire life. He had poured libations to foreign gods. He had bowed down before carved images. He had served as a priest of Midian, officiating over rituals dedicated to powers that were not God. His hands had performed every kind of pagan worship the ancient world had to offer.
And now those same hands were bringing a burnt-offering and peace-offerings to the God of Israel. The very hands that had poured wine before idols were now slaughtering animals on an altar consecrated to the Creator of heaven and earth. The transformation was so complete, so unlikely, that the Torah pauses to let the reader absorb the magnitude of the moment.
This is not a story about gradual change. Yithro did not slowly drift toward monotheism over years of careful study. He heard what God had done, he declared "Blessed is the Lord," and he immediately brought sacrifices. The burnt-offering — the olah, which is consumed entirely on the altar — represented total dedication. Yithro held nothing back. The former idolater gave everything to the God he had only just acknowledged.