So, back to Moses—an Israelite brought up as an Egyptian, so quite likely the first Israelite to be any good at writing, hence ascribing the first five books of the Bible to him. At age 40 he runs away from Egypt. At age 80 he returns to set his people free. And again, readers start to call it impossible. But was he really 80? 40 was well-established as generic term for a “long time” or a “generation.”
Read Numbers 32:13. Did God measure 40 years? And how many generations would have died?
A generation at that time was probably 25 years. Maybe Moses left at age 25 and returned a generation later, with his grown-up kids, at age 50. Where did he go in the meantime, and what did he do?
Read Exodus 2:15. Wells would mark oases or villages and farms.
Midian is the East side of the Gulf of Aqaba. There was a trade route across the (Sinai) desert from Egypt to Midian. Tradition says Moses travelled ten days, corresponding to seven days across the desert and three days down the coast—interesting because after the Jews escape from Egypt they travelled seven days across the desert and three days down the coast to the wells at Meribah. Moses marries a priest’s daughter—presumably a Midianite priest—and looks after his father-in-law’s flocks. In summer he takes the sheep to the good (presumably cooler) pastures… where?
Read Exodus 3:1. Which mountain was this?
“Modern” (4th century initially, popular after 15th century) tradition says Moses went back across the Gulf of Aqaba all the way to the “modern” Mount Sinai, out in the desert. Not a particularly good place to take sheep. Older traditions, and modern practice, would have him march Eastwards to the volcanic mountains where the weather’s cooler and the pasture’s good. Since they’re volcanic, these mountains would be associated with “gods” and the god of the Midianites was in fact called Sin, hence Sinai. (Incidentally, that might be why the Bible keeps changing the name to Mount Horeb.) Of course, on a volcanic mountain, a bush might indeed seem to burn without burning up, and if it wasn’t the Bible, the Exodus account would be hailed as a very early written description of volcanic activity. (In fact, if it wasn’t the Bible, the Exodus account of the God’s appearance on Mount Sinai would be considered an amazingly vivid first-person account of a volcano. But we’ll come to that…)