Exodus 18 can be outlined as follows:
Verses 1 – 4 reintroduces Jethro, a Midianite priest and Moses’ father-in-law. It recalls the fact that Moses sent his wife and children back home to Jethro. It also provides added information about Moses’ two sons.
Verses 5 – 12 describe the time when Jethro came to visit Moses in the wilderness near Mount Sinai. He was accompanied by Moses’ wife Zipporah and Moses’ two son, Gershom and Eliezer. After joyfully greeting Jethro, Moses described all of the events from the deliverance to the Red Sea onward. Jethro responded by praising the LORD and offering sacrifices to the God of Israel.
The day after Jethro, Moses, Aaron, and the elders celebrated a sacrificial to honor the LORD, Moses went about his usual duties in managing the affairs of the people. On this day, his job was to mediate disputes and dispense justice when there was an issue between Israelites. This was an extremely burdensome task to Moses because it lasted all day. Jethro saw what it was doing to Moses and spoke to him about the wisdom of training others to share the responsibility of governing.
Having heard his father-in-law’s advice, Moses implemented it. He appointed men at the various levels to do the judging of the less difficult matters, leaving only the most difficult ones to be brought to Moses. Once this was done, Jethro left to go back to his home in Midian.