Exodus 17 : 1-7

The whole community of the people of Israel moved on from the desert of Sin going from place to place as YHVH commanded, and encamped at Rephidim. But there was no water to drink. The people complained to Moses and said, “Give us water to drink.” But Moses replied, “Why do you find fault with me? Why do you put YHVH to the test?”

But the people thirsted for water there and grumbled against Moses, “Why did you make us leave Egypt to have us die of thirst with our children and our cattle?”

So Moses cried to YHVH, “What shall I do with the people? They are almost ready to stone me!” YHVH said to Moses, “Go ahead of the people and take with you the elders of Israel. Take with you the staff with which you struck the Nile, and go. I will stand there before you on the rock at Horeb. You will strike the rock and water will flow from it and the people will drink.”

Moses did this in the presence of the elders of Israel. The place was called Massah and Meribah because of the complaints of the Israelites, who tested YHVH saying, “Is YHVH with us or not?”