Exodus 17:5-7

5The Lord said to Moses, “Go over before the people; take with you some of the elders of Israel and take in your hand your staff with which you struck the Nile and go.

6I will be standing before you there on the rock in Horeb, and you will strike the rock, and water will come out of it so that the people may drink.” And Moses did so in plain view of the elders of Israel.

7He called the name of the place Massah and Meribah, because of the contending of the Israelites and because of their testing the Lord, saying, “Is the Lord among us or not?”