At one level, the brief account in Numbers 17 wraps up the report of the rebellions in the previous chapter. God wishes to rid himself of the constant grumbling of the Israelites as they challenge Aaron’s priestly authority (17:5). So the staff of the ancestral leader of each tribe is carefully labeled and then secreted by Moses, as directed, in the tabernacle, the “Tent of Testimony.” God declares, in advance, that the staff belonging to the man he chooses will sprout.
Moses does as he is told. The next morning he fetches the twelve staffs. Aaron’s staff, and only his staff, has budded — indeed, it has budded, blossomed, and produced almonds. This staff, by God’s instruction, is preserved for posterity. As for the Israelites, it dawns on them that their rebellion was not just against a couple of men, Aaron and Moses, but against the living God. Now they cry, “We will die! We are lost, we are all lost! Anyone who even comes near the tabernacle of the LORD will die. Are we all going to die?” (17:12–13).
What shall we make of this account?
(1) The response of the Israelites is partly good, but is still horribly deficient. It is good in that this event, at least for the time being, prompts them to see that their rebellion was not against Moses and Aaron alone, but against the living God. Fear of God can be a good thing. Yet this sounds more like the cringing fear of people who do not know God very well. They are afraid of being destroyed, but they are not in consequence more devoted to God. In Numbers 20 and 21, the people are whining and grumbling again; this miraculous display of the staff that budded settled nothing for very long. That, too, is horribly realistic: the church has a long history of powerful revivals that have been dissipated or prostituted within a short space of time.
(2) One must ask why God attaches so much importance to the fact that only the designated high priest may perform the priestly duties. We must not infer that this is the way we should defer to all Christian leaders. Within the canonical framework, much more than this is at stake in the account of Aaron’s rod that budded. The point is that only God’s prescribed high priest is acceptable to God for discharging the priestly office. As the opening lines of Numbers 18 make clear, only Aaron and his sons are to “bear the responsibility for offenses against the sanctuary and . . . priesthood.” The New Testament insists, “No one takes the honor upon himself; he must be called by God, just as Aaron was” (Heb. 5:4). So also Christ (Heb. 5:5)! Only God’s appointed priest will do.
Source: For The Love of God by Don Carson (Following Robert Murray Mccheyne reading plan)