Exodus 17:1-6

Then all the congregation of the children 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 so we may [have something to] drink.” And Moses said to them, “Why do you quarrel with me? Why do you tempt the LORD and try His patience?” But the people were thirsty for water; and the people murmured against Moses and said, “Why did you bring us up from Egypt to kill us and our children and our livestock with thirst?” So Moses cried out to the LORD for help, saying, “What shall I do with this people? They are almost ready to stone me.” Then the LORD said to Moses, “Pass before the people and take 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; there you shall strike the rock, and water will come out of it, so that the people may [have something to] drink.” And Moses did so in the sight of the elders of Israel. [1 Cor 10:4]