Deuteronomy 9:21

21. I cast the dust thereof into the brook that descended out of the mount—that is, "the smitten rock" (El Leja) which was probably contiguous to, or a part of, Sinai. It is too seldom borne in mind that though the Israelites were supplied with water from this rock when they were stationed at Rephidim (Wady Feiran), there is nothing in the Scripture narrative which should lead us to suppose that the rock was in the immediate neighborhood of that place (see on :-). The water on this smitten rock was probably the brook that descended from the mount. The water may have flowed at the distance of many miles from the rock, as the winter torrents do now through the wadies of Arabia-Petræa (Psalms 78:15; Psalms 78:16). And the rock may have been smitten at such a height, and at a spot bearing such a relation to the Sinaitic valleys, as to furnish in this way supplies of water to the Israelites during the journey from Horeb by the way of mount Seir and Kadesh-barnea (Deuteronomy 1:1; Deuteronomy 1:2). On this supposition new light is, perhaps, cast on the figurative language of the apostle, when he speaks of "the rock following" the Israelites (Deuteronomy 1:2- :) [WILSON, Land of the Bible].