And Moses lifted up his hand, and with his rod he struck the rock twice: and the water came out abundantly, and the congregation drank, and their animals also.
Read Chapter 20
Augustine of Hippo
AD 430
We recognize that we are taking a trip in a wasteland. If we recognize ourselves in a wasteland, we are in a wasteland. What does it mean, in a wasteland? In a desert. Why in a desert? Because in this world, one thirsts on a waterless road. But let us thirst that we may be filled. For “blessed are they who hunger and thirst for justice; for they shall have their fill.” And our thirst is filled from a rock in the wasteland. For “the rock was Christ.” And it was struck with a rod that water might flow. But that it might flow, it was struck twice; for there are the two pieces of wood on the cross.
The rock is Christ in a sign, the true Christ in the Word and in the flesh. And how did they drink? The rock was struck twice with a rod. The double striking prefigures the two pieces of wood on the cross. .
“Therefore Moses struck the rock twice with his staff.” What does this mean, brethren? I do not think it is without mystery. What does it mean that the rock was not struck once but twice with the staff? The rock was struck a second time because two trees were lifted up for the gibbet of the cross: the one stretched out Christ’s sacred hands, the other spread out his sinless body from head to foot.
The rock. This rock was a figure of Christ, and the water that issued out from the rock, of his precious blood, the source of all our good; (Challoner) while the striking twice with the rod, denoted the cross, composed of two pieces of wood. (St. Augustine, q. 35.) (Worthington)
Priests also must take care lest they be insincere, lest they doubt the power of God. If Aaron and Moses (who seemed to waver at the waters of contradiction) did not deserve to enter the Promised Land, does it not stand to reason that we, bent under the burden of sin, shall be far less able to cross the river Jordan and reach Gilgal, the place of circumcision, if we shall cause one of these little ones to sin? Homily