Numbers 20:10 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. 12 And 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.
When Moses was commanded by God to smite The Rock the first time, that smiting signified the death of Christ on Calvary, when He would be smitten for our sins. Thus, He was to be smitten only once, and not twice, for He was to die only once, to make the atonement for us certain.
After Jesus died, the way was opened up for all of humanity to simply speak to Him, and thus, when in anger, Moses struck The Rock twice, the symbolism was greatly distorted. That this single act of Moses caused the revelation of God to humanity as it was to pertain to The Rock, to be damaged, can be seen in the reaction of God to the double smiting.
God commanded Moses in this instance to speak to The Rock, and it would bring forth water, but again, the scriptures must be studied line upon line so that the true meaning may be made manifest, for in the New Testament we find Jesus referring to Himself as The Living Water, which if any person partakes of, they would never thirst again.
John 7:37 In the last day, that great day of the feast, Jesus stood and cried, saying, If any man thirst, let him come unto me, and drink. 38 He that believeth on me, as the scripture hath said, out of his belly shall flow rivers of living water.
May The Lord add His blessing to the study of His word. God bless!