Sforno on Exodus 18:12/ספורנו על שמות י״ח:י״ב

1עולה וזבחים לאלוקים. This was intended as a symbol of Yitro’s acceptance of the yoke of Heaven. A similar symbolic acceptance is found in Kings II 5,17 when the general Naaman undertakes never again to offer such sacrifices as עולה וזבחים to any deities other than the G’d in heaven.

2לאכול לחם עם חותן משה, to rejoice with him on his entry into the select circle of those who serve the only true G’d, the Creator of the universe. He joined the ranks of those who are described by David in Psalms 149 as ישמח ישראל בעושיו, “Israel rejoices in Him Who has proved to be its Creator.”

3לפני האלוקים. in front of the altar on which they offered these sacrifices. It is not clear if this was the altar Moses had built after the victory over Amalek (in the event Yitro had arrived before the revelation at Mount Sinai) or if it had been another altar whose erection had not been especially mentioned by the Torah. At any rate, the consuming of the offerings known as זבחים, “meat-offerings,” took place within view of the altar.