Exodus 17:2-6

2Therefore 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?”

3And 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?”

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

5And 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.

6Behold, 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.