Before Moses is able to leave for Egypt, he has to ask permission from his father-in-law, Jethro.
This is an odd statement for a couple of reasons. First off, why does Moses have to ask permission from someone like this, and second, I thought a man named Reuel was his father-in-law (Exodus 2:18)?
Unsurprisingly, there is a whole field of Biblical research into the study of Reuel and Jethro that we don’t have space for here. Some popular assumptions are that Reuel was the grandfather and Jethro was the dad, or that Reuel was his actual name and Jethro was his title.
I personally believe that they’re the same person. It’s not uncommon in Scripture for people to have varying names for different purposes (Saul/Paul, Cephas/Peter, Abram/Abraham, Jacob/Israel).
Also, keep in mind that the first time Moses met Reuel was forty years earlier. It’s very likely that he grew into a position of some authority, which may have conferred to him a different name. But that’s just my opinion; if this is an area that you’re passionate in, I would love to hear from you.
All we really know is that he’s a person of some honor. The very fact that Moses has to ask him for permission to leave shows that he may even be a tribal chief in Midian. Exodus 3:1 claims that he’s a “priest of Midian,” which, in those days, would have been a part of the aristocracy.
Jethro is also a deeply religious man. When Moses meets him after the Exodus from Egypt, Jethro is effusive in his praise for Jehovah. He offers sacrifices, eats a meal with Israelite leaders, and proclaims Jehovah as “greater than all the gods” (Exodus 18:9-12).
But Jethro is also a Midianite, which is not a throwaway concept for this particular study. The Midianites were descended from Abraham, but they came from Abraham’s second wife, Keturah (Genesis 25:1-2).
Theoretically, they should’ve been friendly with the Israelites, but their history with God’s people is anything but. They’re the ones who buy Joseph from his brothers (Genesis 27:28). In Judges 6, it’s the Midianites who so oppress Israel that God calls Gideon to drive them out.
Arguably the most awkward interaction is when God commands Moses to “be hostile to the Midianites and kill them.” Along with the Moabites, they were the ones that hired Balaam to curse Israel (among other things). Because of that, God wanted them punished (Numbers 25:17-18).
Why is this awkward? Because it’s these very people that Jethro and Zipporah, Moses’ wife, came from. It’s also the people that Moses made his home with for forty years.
But Jethro himself is a great asset for Moses. He’s the one that counsels Moses to divide up the people and establish judges over the groups, so as not to “wear himself out” (Exodus 18:18). This manner of administration shows Jethro’s wisdom in managing large groups – a concept that Moses might not have been immediately familiar with, but he would need to learn very quickly.