Moses obtained water out of a rock by beating it with his staff
(Exodus 17:2-6)

This miracle possibly refers to a rare but well documented geological phenomenon

In the 1930s, a British officer named major Jarvis witnessed something miraculous in the Sinai desert:

Some of the Sinai Camel Corps had halted in a wadi [a dried up river stream] and were digging in the loose gravel to obtain water that was slowly trickling through the limestone rock.

The men were working slowly and the Sergeant said “Give it to me” and, seizing a shovel from one of the men, he began to dig with great vigour. One of his lusty blows hit the rock, when the polished hard face that forms on weathered limestone cracked and fell away, exposing the soft porous rock beneath, and out of the porous rock came a great gush of clear water.

It is regrettable that the Sudanese Camel Corps hailed their Non-Commissioned Officer with shouts of: “What ho, the prophet Moses!”

Indeed. According to Exodus, Moses performed roughly the same trick in the desert after he led the Israelites out of Egypt. Near Mount Horeb (the mountain where Moses saw his burning bush), Moses miraculously obtains water out of a rock by slamming it:

The LORD answered Moses, "Walk on ahead of the people. Take with you some of the elders of Israel and take in your hand the staff with which you struck the Nile, and go. I will stand there before you by the rock at Horeb. Strike the rock, and water will come out of it for the people to drink." So Moses did this in the sight of the elders of Israel. (Ex 17:5-6)

Geologists have a pretty ordinary explanation for the ‘miracle’. It comes about when a porous rock fills up with water and then grows a ‘crust’ on the outside by weathering. The water is locked up inside, until you slam its crust off.

Yet, it doesn’t seem very plausible that Moses really ran into one of those special rocks. For starters, one ‘gush of clear water’ obviously isn’t enough to feed hundreds of thousands of Israelites.

What’s more, it would have been an incredible coincidence if Moses really ran into a ‘water rock’.

The phenomenon is rare. And Moses and the Israelites encountered a long list of rare things, like manna from heaven, birds falling down, and a moving column of smoke and fire showing the way.

That’s just too much coincidence, for one walk through the desert!

Theologists have another explanation. They point out that in religious writing, the rock miracle isn’t without precedent.

In mythology, finding freshwater has always been considered a pretty supernatural feat in itself – let alone finding water in the desert. There are many stories about prophets, saints and other holy people who found water: from pharao Rameses II in Egypt to saint Bernadette in France.

In that respect, Moses was only doing his job as a miracle man. For a holy guy running about in the desert, finding water in some miraculous manner would have been the only proper thing to do.

It doesn’t matter if Moses really performed the miracle or not. Bottom line is that the author of Exodus is telling us: “Look how holy Moses is! He’s doing the water thing!”

And of course, it can’t be ruled out that somewhere down the line, the ‘miracle’ really is connected to the thing with the porous desert rock.

It is conceivable that the desert rock phenomenon somehow ended up in local folklore as a miracle, and that an adapted version was recorded in Exodus later on. But we’ll never know for sure.

Colin Humphreys, “The miracles of Exodus” (2003)