The incident of Moses striking the rock twice is described in Numbers 20:1-13. Here's an explanation of why Moses hit the rock and why it was considered a significant transgression:

The Context

1. The Israelites were in the Desert of Zin and there was no water for the community36.

2. The people gathered in opposition to Moses and Aaron, complaining about the lack of water36.

3. God instructed Moses to take his staff, gather the assembly, and speak to the rock to bring forth water34.

Moses' Actions

1. Instead of speaking to the rock as God commanded, Moses struck the rock twice with his staff34.

2. Water came out abundantly, and the people and their livestock drank3.

Why It Was Considered a Sin

1. Disobedience: Moses directly disobeyed God's specific instructions to speak to the rock34.

2. Lack of Trust: Moses' actions demonstrated a lack of faith in God's ability to provide water through speaking alone5.

3. Taking Credit: Moses said, "Must we bring you water out of this rock?" seemingly taking credit for the miracle rather than attributing it to God34.

4. Anger and Frustration: Moses acted out of frustration with the people, calling them "rebels" before striking the rock56.

5. Disrupting Biblical Typology: The rock was meant to be a symbol of Christ. Striking it once (as in Exodus 17) represented Christ's sacrifice, but striking it again disrupted this symbolism34.

Consequences

As a result of this transgression, God declared that Moses and Aaron would not lead the Israelites into the Promised Land36.

This incident highlights the importance of obedience, faith, and proper representation of God's character, even for leaders as prominent as Moses. It serves as a reminder that God holds His chosen leaders to a high standard and that seemingly small acts of disobedience can have significant consequences.