Moses’ father-in-law, Jethro, comes to visit after hearing all the big things going on. He brings Moses’ wife and sons with him.
Jethro watched Moses as judge for the people who stand and wait all day long. He suggests the idea that Moses appoint judges to handle the easy cases and send the tough ones to him. Moses agreed and Jethro goes home.
I assume Jethro was already an Israelite, since he’s name as a priest of Midian. I can imagine Moses married a non-Israelite. So there were those who were not in slavery in the land nearby, which isn’t mentioned at all. It’s assumed that the entirety of the Israelite people are following Moses in the wilderness.
Jethro’s suggestion is an excellent one, but I wonder why neither Moses nor the LORD thought of it until now.