Exodus 17:1-6

All the congregation of the people of Israel moved on from the wilderness of Sin by stages, according to the commandment of the LORD, and camped at Rephidim, but there was no water for the people to drink. Therefore the people quarreled with Moses and said, “Give us water to drink.” And Moses said to them, “Why do you quarrel with me? Why do you test the LORD?” But the people thirsted there for water, and the people grumbled against Moses and said, “Why did you bring us up out of Egypt, to kill us and our children and our livestock with thirst?” So Moses cried to the LORD, “What shall I do with this people? They are almost ready to stone me.” And the LORD said to Moses, “Pass on before the people, taking with you some of the elders of Israel, and take in your hand the staff with which you struck the Nile, and go. Behold, I will stand before you there on the rock at Horeb, and you shall strike the rock, and water shall come out of it, and the people will drink.” And Moses did so, in the sight of the elders of Israel.