Flavius Josephus, Antiquities of the Jews
William Whiston, A.M., Ed.

[33] As soon as they were removed thence, they came to Rephidim, being distressed to the last degree by thirst; and while in the foregoing days they had lit on a few small fountains, but now found the earth entirely destitute of water, they were in an evil case. They again turned their anger against Moses; but he at first avoided the fury of the multitude, and then betook himself to prayer to God, beseeching him, that as he had given them food when they were in the greatest want of it, so he would give them drink, since the favor of giving them food was of no value to them while they had nothing to drink. And God did not long delay to give it them, but promised Moses that he would procure them a fountain, and plenty of water, from a place they did not expect any. So he commanded him to smite the rock which they saw lying there, ¹ with his rod, and out of it to receive plenty of what they wanted; for he had taken care that drink should come to them without any labor or pains-taking. When Moses had received this command from God, he came to the people, who waited for him, and looked upon him, for they saw already that he was coming apace from his eminence. As soon as he was come, he told them that God would deliver them from their present distress, and had granted them an unexpected favor; and informed them, that a river should run for their sakes out of the rock. But they were amazed at that hearing, supposing they were of necessity to cut the rock in pieces, now they were distressed by their thirst and by their journey; while Moses only smiting the rock with his rod, opened a passage, and out of it burst water, and that in great abundance, and very clear. But they were astonished at this wonderful effect; and, as it were, quenched their thirst by the very sight of it. So they drank this pleasant, this sweet water; and such it seemed to be, as might well be expected where God was the donor. They were also in admiration how Moses was honored by God; and they made grateful returns of sacrifices to God for his providence towards them. Now that Scripture, which is laid up in the temple, ² informs us, how God foretold to Moses, that water timid in this manner be derived out of the rock.'