Thus begins the account of events that led to the exclusion of Moses and Aaron from the Promised Land. Evidently the water provided for them since the miracle at Horeb (Ex. 17:1-7) some 40 years ago had now been cut off. This was brought about by God in order to test the faith of the new generation that had grown up in the wilderness (see PP 411).
Against Moses.
Compare Ex. 17:2, 3, where their fathers had manifested the same spirit.