1 And all the congregation of the children of Israel journeyed from the wilderness of Sin after their journeys, according to the commandment of the LORD, and encamped in Rephidim. And there was no water for the people to drink. 2 Therefore, the people contended with Moses and said, "Give us water so that we may drink." And Moses said to them, "Why do you chide with me? Why do you test the LORD?" 3 And the people thirsted there for water. And the people murmured against Moses and said, "Why is this that you have brought us out of Egypt to kill us, our children, and our cattle with thirst?" 4 And Moses cried to the LORD, saying, "What shall I do to this people? They are almost ready to stone me." 5 And the LORD said to Moses, "Go on before the people and take with you some of the elders of Israel. And also take in your hand your rod with which you smote the river, and go. 6 Behold, I will stand before you there on the rock in Horeb. And you shall smite the rock, and water shall come out of it so that the people may drink." And Moses did so in the sight of the elders of Israel. 7 And he called the name of the place Massah and Meribah because of the chiding of the children of Israel and because they tested the LORD, saying, "Is the LORD among us, or not?"
8 Then Amalek came and fought with Israel in Rephidim. 9 And Moses said to Joshua, "Choose for us men and go out, fight with Amalek. Tomorrow I will stand on the top of the hill with the rod of God in my hand." 10 So Joshua did as Moses had said to him and fought with Amalek. And Moses, Aaron, and Hur went up to the top of the hill. 11 And it came to pass, when Moses held up his hand, that Israel prevailed. And when he let down his hand, Amalek prevailed. 12 But Moses's hands were heavy, and they took a stone and put it under him, and he sat upon it. And Aaron and Hur supported his hands, one on one side and the other on the other side. And his hands were steady until the going down of the sun. 13 And Joshua completely defeated Amalek and his people with the edge of the sword.
14 And the LORD said to Moses, "Write this for a memorial in a book and rehearse it in the ears of Joshua, for I will utterly blot out the remembrance of Amalek from under heaven." 15 And Moses built an altar and called its name Yahweh is My Banner, 16 For he said, "Because the LORD has sworn that the LORD will have war with Amalek from generation to generation."
[v.1-7] - This is the encounter at the rock in Horeb, which is a type and shadow of Christ. God instructs Moses to strike an appointed rock in Horeb and then God causes water to come out of the rock for the people to drink. Paul shows this to be a type and shadow of Christ in 1st Corinthians 10:4, which says, "And all drank the same spiritual drink (for they drank of that spiritual Rock which followed them, and that Rock was Christ)." In John 7:37-39, Jesus makes reference to flowing rivers of living waters. He is referencing the Holy Spirit. The parallel is this: strike the rock, receive the waters; believe in Christ, receive the Spirit. Christ is the Rock we must strike, putting our faith in Him to give us the living waters of the Holy Spirit. Reference, Isaiah 44:3, 55:1; John 4:10; Revelation 21:6. See also the comment for Numbers 20:2-13.
[v.7] - Reference, Psalm 81:7, 95:8-9.
[v.8-13] - This is the first war fought by the Israelites. This battle gives us a picture of Christ. He is like Joshua in that He is with us fighting our battles. He is like Moses in that He is up above us, making intercession to the Father on our behalf. The difference is this: He does not faint, neither does He grow weary; He is everlasting (Isaiah 40:28).
[v.9] - This is the first mention of Joshua. From Matthew Henry's Commentary: "He is nominated commander-in-chief in this expedition, that he might be trained up to the services he was designed for after the death of Moses, and be a man of war from his youth." See also the notes on Numbers 13:16.
[v.14] - The actions of Amalek are to be recorded in a book, esse memorial perpetuum, that is, to be a perpetual, or continual memorial. This is memorialized because the remembrance of Amalek is to be utterly blotted out, or as it says in verse 16, "the LORD has sworn that the LORD will have war with Amalek from generation to generation." This was fulfilled by David as told in 1st Samuel, chapter 30, and mentioned in 2nd Samuel 1:1 and 8:12. Reference, Numbers 24:20.
[v.15] - "Yahweh is My Banner" - From John Gill's Exposition: "This may fitly be applied to Christ, who is both altar, sacrifice, and priest, and who is the true [Yahweh], and after so called; and who is lifted up as a banner, standard, or ensign in the everlasting Gospel, in order to gather souls to him, and enlist them under him, and to prepare them for war, and encourage them in it against their spiritual enemies; and as a token of their victory over them, and a direction to them where they shall stand, when to march, and whom they shall follow; and to distinguish them from all other bands and companies, and for the protection of them from all their enemies, see Isaiah 11:10."