To refresh your memory of what is happening to Israel. They had refused to believe that God was able to give them the promised land, so God had sent them out into the wilderness until every man over 20 years (at that time) has died.
V.1 You remember that when they had been brought through the Red Sea, Miriam, Moses’ and Aaron’s sister, had sung a joyful song (Ex. 15:20-2120And Miriam the prophetess, the sister of Aaron, took a timbrel in her hand; and all the women went out after her with timbrels and with dances. 21And Miriam answered them, Sing ye to the Lord, for he hath triumphed gloriously; the horse and his rider hath he thrown into the sea. (Exodus 15:20‑21)). Now she dies — the remembrance of Israel’s first joy passes into sorrow. Isn’t that just like us? The early joy of salvation, soon passes away, when we are disobedient to God. See Numbers 13:17,17And Moses sent them to spy out the land of Canaan, and said unto them, Get you up this way southward, and go up into the mountain: (Numbers 13:17) but particularly verse 26 for what had happened 38 years before. Now they are back to Kadesh!
V.2-5 Israel not only forgot their earlier joy, but forgot the power of a loving God which was able to care for their every need. Read this bitter attack on Moses and Aaron.
V.6 Once again Moses and Aaron control themselves, go quietly from the complaining people to a compassionate LORD! The right Person and the right place.
V.7-9 “The rod” is Aaron’s. Aaron’s rod is a picture of grace, the rod of Moses is a picture of power. Moses is told to speak to the rock. The rock had been struck once (Ex. 17). This is a picture of the cross of Christ — read Heb. 10:1212But this man, after he had offered one sacrifice for sins for ever, sat down on the right hand of God; (Hebrews 10:12) “one offering;” also Psa. 78:1515He clave the rocks in the wilderness, and gave them drink as out of the great depths. (Psalm 78:15). Speaking to it, introduces to us the power of the Holy Spirit Who sustains us over and over again, during “our wilderness journey” here on earth today. Just speaking, not smiting.
V.10-11 Moses makes serious mistakes. (1) Uses his own rod, and (2) smites the rock twice. The Lord is gracious! The water flows out, BUT ...
V.12 Moses is told the consequences of his acts — he will not lead God’s people into the land! Although believers often are disobedient to the Word of God, the Lord graciously has mercy, but He cannot, and will not reward disobedience. We today don’t look for approval for our acts by results we can see, but we get the assurance of our approval from the Word of God.