He responded in kind, chiding the children of Israel, “ . . must we fetch you water out of this rock?” And he smote the rock twice for emphasis!
It was not necessary. God had directed him to speak to the rock. Nothing else was required. Speaking to the rock would be a teaching for the people. They would hear and see and know how they should handle problems to come.
Moses’ action was confusing at best – taunt the people, beat the rock? Could this be the pattern to follow? It would surely result in useless demonstrations — knowing they needed a demonstration of power, he shouted and slapped the pulpit.
By striking the rock, Moses had demonstrated his power with God, not God’s power that is available to all. By not speaking to the rock, Moses had first not demonstrated how we are to resolve problems; by speaking to the problem as directed by God. More importantly, he had disobeyed God, and because of this, he would not enter the Promised Land.
Numbers 20:2-12 (KJV) And there was no water for the congregation: and they gathered themselves together against Moses and against Aaron. {3} And the people chided with Moses, and spake, saying, Would God that we had died when our brethren died before the LORD! {4} And why have ye brought up the congregation of the LORD into this wilderness, that we and our cattle should die there? {5} And wherefore have ye made us to come up out of Egypt, to bring us in unto this evil place? it is no place of seed, or of figs, or of vines, or of pomegranates; neither is there any water to drink. {6} And Moses and Aaron went from the presence of the assembly unto the door of the tabernacle of the congregation, and they fell upon their faces: and the glory of the LORD appeared unto them. {7} And the LORD spake unto Moses, saying, {8} Take the rod, and gather thou the assembly together, thou, and Aaron thy brother, and speak ye unto the rock before their eyes; and it shall give forth his water, and thou shalt bring forth to them water out of the rock: so thou shalt give the congregation and their beasts drink. {9} And Moses took the rod from before the LORD, as he commanded him. {10} And Moses and Aaron gathered the congregation together before the rock, and he said unto them, Hear now, ye rebels; must we fetch you water out of this rock? {11} And Moses lifted up his hand, and with his rod he smote the rock twice: and the water came out abundantly, and the congregation drank, and their beasts also.{12} And the LORD spake unto Moses and Aaron, Because ye believed me not, to sanctify me in the eyes of the children of Israel, therefore ye shall not bring this congregation into the land which I have given them.