But the Lord said to Moses and Aaron, “Because you did not trust in me enough to honor me as holy in the sight of the Israelites, you will not bring this community into the land I give them.”
Numbers 20:12

In Numbers 20, the Israelites again are complaining. This time, they are complaining about how they have no water and wished they would have been killed in the previous plague (Numbers 20:3).

The Lord instructs Moses and Aaron to speak to a rock and water will come forth from it. However, instead of speaking to the rock, Moses hits the rock twice and water comes from it (Numbers 20:11).

This did not please the Lord because Moses and Aaron did not do what the Lord had asked them to do. So the Lord said that Moses and Aaron will not enter the promise land (Numbers 20:12). At the end of Numbers 20, Aaron passes away.

Why did Moses strike the rock instead of speaking to the rock?

If we look at the situation in Numbers 20, it is similar to a past event found in Exodus 17. In Exodus 17, the Israelites were complaining there was no water and the Lord tells Moses to strike a rock.

Here in Numbers 20, before Moses strikes the rock, he asks the people, “Listen, you rebels, must we bring water of this rock?” (Numbers 20:10, emphasis mine).

Moses saw that this was a similar situation and did what worked previously. Moses did not believe speaking to the rock would make water come. Moses doubted the Lord.

Even though water did come out, because the Lord is faithful, even when we’re not (2 Timothy 2:13), the cost of the action was that Moses and Aaron would not go into the promise land.

My friends, God is a living being. He does not always do the same thing even if the situations are similar. Jesus healed many blind people, but they were all not healed in the same way. Jesus used mud to heal one guy (John 9), for another man, Jesus spits on his eyes (Mark 8:22-26), for some, he touched their eyes (Matthew 9:27-31, 20:29-34), and one was healed immediately at His word (Mark 10:46-52).

When you enter a new situation that is similar to a previous situation, do not lean on your own understanding, but trust the Lord (Proverbs 3:5-6). If God told you to do Action A the first time but now telling you to do Action B for the second time, do Action B. Even though it might not make sense at the time, and doing Action A might get the same initial result, not fully trusting God will never end well. You can ask Moses and Aaron.

Trust in the Lord with all your heart, and do not lean on your own understanding.

In all your ways acknowledge him, and he will make straight your paths.

Proverbs 3:5-6