John Calvin Commentary Numbers 17:10

"And Jehovah said unto Moses, Put back the rod of Aaron before the testimony, to be kept for a token against the children of rebellion; that thou mayest make an end of their murmurings against me, that they die not." — Numbers 17:10 (ASV)

And the Lord said to Moses. What God had prescribed concerning the censers, He now commands concerning the rod, that is, that it should be preserved as a monument for future ages. This is because people are forgetful and slow to consider His works; and not only that, but they also bury their memory as if with deliberate malice. Therefore, He commands, and not without reproach, that this sign should be stored safely, saying that this is done on account of their perversity.

At the same time, however, He commends His paternal love and pity, because while He chastises their pride, He also provides for their welfare. For, as they were given to rebellion, they would still have provoked His wrath by new murmurings. He says, then, that He anticipates them and restrains their impetuous fury, so that they would not die. Thus, in humbling us, He not only punishes our transgressions, but He also considers what is profitable for us and proves that He cares for us.