Charles H. Spurgeon on Psalms 106:33

They provoked his spirit, etc. Angry he certainly was; and when, reverting to a former miracle, the Most High directed him to take the wonder staff —his rod of many miracles and at the head of the congregation "speak to the rock", and it would "give forth its water", in the heat and agitation of his spirit he failed to implement implicitly the Divine command. Instead of speaking to the rock he spoke to the people, and his harangue was no longer in the language calm and dignified of the lawgiver, but had a certain tone of petulance and egotism. "Hear now, ye rebels, must we —must I and Aaron, not must Jehovah —fetch you water out of this rock?" And instead of simply speaking to it, he raised the rod and dealt it two successive strokes, just as if the rock were sharing the general perversity, and would no more than the people obey its Creator's bidding. He was angry, and he sinned. He sinned and was severely punished. Water flowed sufficient for the whole camp and the cattle, clear, cool, and eagerly gushing, enough for all the million; but at the same moment that its unmerited bounty burst on you, ye rebels, "a cup of wrath was put into the hand of Moses." (Van Oosterzee.) To you, ye murmurers, there came forth living water; to your venerable leaders the cup of God's anger. "The Lord spoke 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." Nu 20:12. James Hamilton.