And the LORD said unto Moses, Go on before the people, and take with thee of the elders of Israel; and thy rod, wherewith thou smotest the river, take in thine hand, and go.

Wesley's Notes

17:5 Go on before the people - Though they spake of stoning him. He must take his rod with him, not to summon some plague to chastise them, but to fetch water for their supply. O the wonderful patience and forbearance of God towards provoking sinners! He maintains those that are at war with him, and reaches out the hand of his bounty to those that lift up the heel against him. If God had only shewed Moses a fountain of water in the wilderness, as he did to Hagar, not far from hence, Gen 21:19, that had been a great favour; but that he might shew his power as well as his pity, and make it a miracle of mercy, he gave them water out of a rock. He directed Moses whither to go, appointed him to take of the elders of Israel with him, to be witnesses of what was done, ordered him to smite the rock, which he did, and immediately water came out of it in great abundance, which ran throughout the camp in streams and rivers, Psa 78:15,16, and followed them wherever they went in that wilderness: God shewed his care of his people in giving them water when they wanted it; his own power in fetching it out of a rock, and put an honour upon Moses in appointing the water to flow out upon his smiting of the rock. This fair water that came out of the rock is called honey and oil, Deu 32:13, because the people's thirst made it doubly pleasant; coming when they were in extreme want. It is probable that the people digged canals for the conveyance of it, and pools for the reception of it. Let this direct us to live in a dependance, Upon God's providence even in the greatest straits and difficulties; And upon Christ's grace; that rock was Christ, 1Cor 10:4. The graces and comforts of the Spirit are compared to rivers of living waters, John 7:38,39 4:14. These flow from Christ. And nothing will supply the needs and satisfy the desires of a soul but water out of this rock. A new name was upon this occasion given to the place, preserving the remembrance of their murmuring, Massah - Temptation, because they tempted God, Meribah - Strife, because they chide with Moses.

Jamieson-Fausset-Brown Bible Commentary

5. the Lord said unto Moses, &c.-not to smite the rebels, but the rock; not to bring a stream of blood from the breast of the offenders, but a stream of water from the granite cliffs. The cloud rested on a particular rock, just as the star rested on the house where the infant Saviour was lodged [Mt 2:9]. And from the rod-smitten rock there forthwith gushed a current of pure and refreshing water. It was perhaps the greatest miracle performed by Moses, and in many respects bore a resemblance to the greatest of Christ's: being done without ostentation and in the presence of a few chosen witnesses (1Co 10:4).

Matthew Henry's Concise Commentary

17:1-7 The children of Israel journeyed according to the commandment of the Lord, led by the pillar of cloud and fire, yet they came to a place where there was no water for them to drink. We may be in the way of duty, yet may meet with troubles, which Providence brings us into, for the trial of our faith, and that God may be glorified in our relief. They began to question whether God was with them or not. This is called their tempting God, which signifies distrust of him after they had received such proofs of his power and goodness. Moses mildly answered them. It is folly to answer passion with passion; that makes bad worse. God graciously appeared to help them. How wonderful the patience and forbearance of God toward provoking sinners! That he might show his power as well as his pity, and make it a miracle of mercy, he gave them water out of a rock. God can open fountains for us where we least expect them. Those who, in this wilderness, keep to God's way, may trust him to provide for them. Also, let this direct us to depend on Christ's grace. The apostle says, that Rock was Christ, 1Co 10:4, it was a type of him. While the curse of God might justly have been executed upon our guilty souls, behold the Son of God is smitten for us. Let us ask and receive. There was a constant, abundant supply of this water. Numerous as believers are, the supply of the Spirit of Christ is enough for all. The water flowed from the rock in streams to refresh the wilderness, and attended them on their way towards Canaan; and this water flows from Christ, through the ordinances, in the barren wilderness of this world, to refresh our souls, until we come to glory. A new name was given to the place, in remembrance, not of the mercy of their supply, but of the sin of their murmuring: Massah, Temptation, because they tempted God; Meribah, Strife, because they chid with Moses. Sin leaves a blot upon the name.