However, once when the Israelites grumbled because of a lack of water, Jehovah God told Moses simply to speak to a certain crag and water would come out. But the people had so exasperated Moses by their grumbling that Moses lost his temper and instead of just speaking to the crag he presumptuously struck the crag with his rod, shouting: “Hear, now, you rebels! Is it from this crag that we shall bring out water for you?”

Num. 20:10