At first glance it might seem odd, or perhaps a bit harsh, that God punished Moses for striking the rock.  There were actually two occasions, about 40 years apart, where Moses struck the rock.  Let’s take a closer look.

First Occasion

Not long after ancient Israel departed Egypt, they complained to Moses that they had no water to drink.

Exo 17:1  Then all the congregation of the children of Israel set out on their journey from the Wilderness of Sin, according to the commandment of the LORD, and camped in Rephidim; but there was no water for the people to drink.
Exo 17:2  Therefore the people contended with Moses, and said, “Give us water, that we may drink.” So Moses said to them, “Why do you contend with me? Why do you tempt the LORD?”
Exo 17:3  And the people thirsted there for water, and the people complained against Moses, and said, “Why is it you have brought us up out of Egypt, to kill us and our children and our livestock with thirst?”

Moses asked God for help.

Exo 17:4  So Moses cried out to the LORD, saying, “What shall I do with this people? They are almost ready to stone me!”

God told Moses to strike the rock with his rod, which he did.

Exo 17:5  And the LORD said to Moses, “Go on before the people, and take with you some of the elders of Israel. Also take in your hand your rod with which you struck the river, and go.
Exo 17:6  Behold, I will stand before you there on the rock in Horeb; and you shall strike the rock, and water will come out of it, that the people may drink.” And Moses did so in the sight of the elders of Israel.

On this first occasion, Moses obeyed God, and God was happy with Moses.  Note that the rock was struck just once.  The significance of this is covered at the end of this article.

Exo 17:7  So he called the name of the place Massah and Meribah, because of the contention of the children of Israel, and because they tempted the LORD, saying, “Is the LORD among us or not?”

Massah means temptation, testing; and Meribah means strife, contention.  So the place was named for what happened.

Second Occasion

Shortly before entering the Promised Land a similar incident occurred.  This was 40 years later, so those who had complained the first time had now died, and the complainers were their children and grandchildren.

Num 20:2  Now there was no water for the congregation; so they gathered together against Moses and Aaron.
Num 20:3  And the people contended with Moses and spoke, saying: “If only we had died when our brethren died before the LORD!
Num 20:4  Why have you brought up the assembly of the LORD into this wilderness, that we and our animals should die here?
Num 20:5  And why have you made us come up out of Egypt, to bring us to this evil place? It is not a place of grain or figs or vines or pomegranates; nor is there any water to drink.”

Like the first occasion, Moses asked God for help.

Num 20:6  So Moses and Aaron went from the presence of the assembly to the door of the tabernacle of meeting, and they fell on their faces. And the glory of the LORD appeared to them.

This time, however, God told Moses to take the rod and speak to the rock. 

Num 20:7  Then the LORD spoke to Moses, saying,
Num 20:8  “Take the rod; you and your brother Aaron gather the congregation together. Speak to the rock before their eyes, and it will yield its water; thus you shall bring water for them out of the rock, and give drink to the congregation and their animals.”
Num 20:9  So Moses took the rod from before the LORD as He commanded him.

So Moses took the rod.  So far so good.

Num 20:10  And Moses and Aaron gathered the assembly together before the rock; and he said to them, “Hear now, you rebels! Must we bring water for you out of this rock?“
Num 20:11  Then Moses lifted his hand and struck the rock twice with his rod; and water came out abundantly, and the congregation and their animals drank.

Clearly Moses was exasperated by the people.  Instead of speaking to the rock as God had commanded, he struck the rock twice!  Moreover, he seemed to be taking some of the glory for himself by saying, “Must we bring water for you”.  It was probably natural for Moses to think of hitting the rock with the rod, as that’s what God commanded him to do 40 years ago.  However, it was not what God commanded him to do this time.

The Punishment

God was not happy with what Moses and Aaron did; and immediately corrected them.

Num 20:12  Then the LORD spoke to Moses and Aaron, “Because you did not believe [aman] Me, to hallow Me in the eyes of the children of Israel, therefore you shall not bring this assembly into the land which I have given them.”
Num 20:13  This was the water of Meribah, because the children of Israel contended with the LORD, and He was hallowed among them.

God said, they didn’t believe Him to hallow Him in the eyes of the people.  The Hebrew word translated believe is aman, which is sometimes translated as faithful, such as in Numbers 12:7.

Num 12:7  Not so with My servant Moses; He is faithful [aman] in all My house.

Since Moses no doubt believed that God would perform the miracle, a better translation of Numbers 20:12 is, “You were not faithful to Me”, rather than, “You did not believe me”.

The punishment, for both Moses and Aaron, was not being allowed into the Promised Land.

Not long after this Aaron died, where a bit more information is given.

Num 20:23  And the LORD spoke to Moses and Aaron in Mount Hor by the border of the land of Edom, saying:
Num 20:24  “Aaron shall be gathered to his people, for he shall not enter the land which I have given to the children of Israel, because you rebelled against My word at the water of Meribah.

God cited rebellion as the reason for the punishment.  God viewed what Moses and Aaron did as rebellion.  Note the expression “gathered to his people” is a euphemism for death.

A bit later on, God told Moses he would die soon and reaffirmed his punishment.

Num 27:12  Now the LORD said to Moses: “Go up into this Mount Abarim, and see the land which I have given to the children of Israel.
Num 27:13  And when you have seen it, you also shall be gathered to your people, as Aaron your brother was gathered.
Num 27:14  For in the Wilderness of Zin, during the strife of the congregation, you rebelled against My command to hallow Me at the waters before their eyes.” (These are the waters of Meribah, at Kadesh in the Wilderness of Zin.)

God reiterated the reason for the punishment, citing rebellion against His command to hallow Him in the eyes of the people. 

Again, shortly before Moses died, God mentioned the reason for his punishment

Deu 32:48  Then the LORD spoke to Moses that very same day, saying:
Deu 32:49  “Go up this mountain of the Abarim, Mount Nebo, which is in the land of Moab, across from Jericho; view the land of Canaan, which I give to the children of Israel as a possession;
Deu 32:50  and die on the mountain which you ascend, and be gathered to your people, just as Aaron your brother died on Mount Hor and was gathered to his people;
Deu 32:51  because you trespassed against Me among the children of Israel at the waters of Meribah Kadesh, in the Wilderness of Zin, because you did not hallow Me in the midst of the children of Israel.
Deu 32:52  Yet you shall see the land before you, though you shall not go there, into the land which I am giving to the children of Israel.”

Here are the explanations God gave at various times for Moses’s and Aaron’s punishment.

You did not believe Me [were not faithful to Me], to hallow Me in the eyes of the children of Israel, Num 20:12.
You rebelled against My word, Num 20:24.
You rebelled against My command to hallow Me at the waters before their eyes, Num 27:14.
You trespassed against Me among the children of Israel, …, you did not hallow Me in the midst of the children of Israel Deu 32:51.

In summary, Moses (and Aaron) disobeyed God and did not hallow Him before the Israelites, which God viewed as rebellion and being unfaithful to Him.  But why did God say He was not hallowed before the eyes of the congregation?  What difference did it make to the people if Moses spoke to the rock or struck it?  Not much if the people didn’t know what God had told Moses, but a huge difference if they did know.  Although it is not explicitly stated in Scripture, it appears that the people heard God when He instructed Moses and Aaron.

Num 20:6  So Moses and Aaron went from the presence of the assembly to the door of the tabernacle of meeting, and they fell on their faces. And the glory of the LORD appeared to them.
Num 20:7  Then the LORD spoke to Moses, saying,

Moses and Aaron went to the door of the tabernacle of meeting, where the LORD spoke to them.  The people would have heard, (unless God spoke in a whisper). 

God’s reason for Moses’ and Aaron’s punishment is now much clearer.  If the people heard God’s instruction to Moses and Aaron, then they knew that Moses and Aaron disobeyed God when Moses struck the rock twice.  In this case, God was not hallowed in the eyes of the people as they had just seen Moses and Aaron disobey Him.

Moses’s Pleading

Later Moses pleaded with God to allow him to enter the Promised Land.

Deu 1:37  The LORD was also angry with me for your sakes, saying, ‘Even you shall not go in there.

Deu 3:23  “Then I pleaded with the LORD at that time, saying:
Deu 3:24  ‘O Lord GOD, You have begun to show Your servant Your greatness and Your mighty hand, for what god is there in heaven or on earth who can do anything like Your works and Your mighty deeds?
Deu 3:25  I pray, let me cross over and see the good land beyond the Jordan, those pleasant mountains, and Lebanon.’
Deu 3:26  “But the LORD was angry with me on your account, and would not listen to me. So the LORD said to me: ‘Enough of that! Speak no more to Me of this matter.

“Enough of that! Speak no more to Me of this matter”, is probably best understood as God saying that His mind is made up and could not be changed.  It was not a prohibition against the topic, but rather a prohibition against trying to change God’s mind.  So had Moses wanted, he was still able to ask God questions to help him understand His decision.

Why did God tell Moses to strike to the rock the first time but speak to it the second time?

The Bible doesn’t answer this question explicitly, but it does provide enough information for a thoughtful response.

The apostle Paul explained that Jesus Christ was the spiritual rock which followed the ancient Israelites, and they drank of it. 

1Co 10:1  Moreover, brethren, I do not want you to be unaware that all our fathers were under the cloud, all passed through the sea,
1Co 10:2  all were baptized into Moses in the cloud and in the sea,
1Co 10:3  all ate the same spiritual food,
1Co 10:4  and all drank the same spiritual drink. For they drank of that spiritual Rock [petra] that followed them, and that Rock [petra] was Christ.

So the rock which Moses struck, from which life-saving waters gushed out, is likened to Jesus Christ who can give us “living water”.

Joh 4:10  Jesus answered and said to her, “If you knew the gift of God, and who it is who says to you, ‘Give Me a drink,’ you would have asked Him, and He would have given you living water.”

Jesus was “struck”, crucified just once.  Thus the rock also was to be struck just once, which explains God’s instruction to Moses to strike the rock once on the first occasion.  Striking the rock more than once would picture Christ being crucified more than once.  Hebrews addresses this.

Heb 6:4  For it is impossible for those who were once enlightened, and have tasted the heavenly gift, and have become partakers of the Holy Spirit,
Heb 6:5  and have tasted the good word of God and the powers of the age to come,
Heb 6:6  if they fall away, to renew them again to repentance, since they crucify again for themselves the Son of God, and put Him to an open shame.

Heb 7:26  For such a High Priest was fitting for us, who is holy, harmless, undefiled, separate from sinners, and has become higher than the heavens;
Heb 7:27  who does not need daily, as those high priests, to offer up sacrifices, first for His own sins and then for the people’s, for this He did once for all when He offered up Himself.

Why then did God command Moses to speak to the rock in Numbers 20?  Perhaps it was meant to picture prayer.

Conclusion

Why did God punish Moses for striking the rock?  Because Moses (and Aaron) disobeyed God and did not hallow Him before the Israelites, which God viewed as rebellion and being unfaithful to Him.  The people no doubt heard God’s instruction to Moses and Aaron, and therefore knew that Moses and Aaron disobeyed God.