He opened the rock, and the waters gushed out
That is, God opened the rock, who before is said to spread the cloud, and bring the quails, for it was a miraculous affair; or Moses, by divine orders, which was done by smiting it, when waters flowed out in great abundance, sufficient to give drink to men and beasts, and which continued, ( Exodus 17:6 ) ( Numbers 20:11 ) . This was typical of Christ the Rock, ( 1 Corinthians 10:4 ) , and of the opening of his side, from whence flowed blood and water, ( John 19:34 ) and of his being smitten with the rod of justice, and by the law of Moses, from whom flow abundance of grace, and the blessings of it, freely to all his people; (See Gill on Psalms 78:15). (See Gill on Psalms 78:16).
They ran in the dry places like a river;
and did not sink and soak into them, but continued their flow, and followed the Israelites, wherever they went; see ( 1 Corinthians 10:4 ) .