First off, let me chuckle at the title of the first section of Chapter 17:
The budding of Aaron’s rod
OK, it’s out of my system now. Anyway, quick summary of Chapter 17 is that God wants to stop all the complaints of the Israelites toward Moses by choosing the staff of one of the leaders of the twelve houses, including Aaron who will represent the House of Levi. God will do this by causing one of the staffs to sprout. Gee, I wonder who will win. Obviously, Aaron’s is the chosen staff.
So, I have a problem with these two chapters because it gives away the game. Moses and Aaron were already the defacto leaders of this group and were the only ones who God “spoke” to and who had access to the tent of meeting. So they could have set this all up like a parlor trick in order to keep their hold on power.
In Chapter 18 God tells Aaron that, as the one responsible for the sanctuary, he and his Levite brothers have the right to eat the offerings of the people because they are holy. These offerings include the first fruits of the harvest, the best animals, and shekels of silver (obviously they won’t eat those). They are told that only they are to approach the tent of meeting and that anyone else that approaches will die. That’s a good way to keep people away, by issuing a stern warning and a threat of death.