Psalms 114:8

Which turned the rock into a standing water -That is, Before him who could do this, the earth should tremble; the inhabited world should stand in awe of such amazing power. The words rendered “a standing water,” mean properly a pool of water. They indicate nothing in regard to the permanency of that pool; they do not imply that it remained as a standing pool during the sojourn of the Israelites in the wilderness - whatever may have been the fact in regard to that. The simple idea is, that, at the time referred to, the rock was converted into a pool; that is, the waters flowed from the rock, constituting such a pool.