At Rephidim the people's thirst turns into a quarrel. Their question, Is Yahweh among us, or not?, reveals unbelief despite the pillar of cloud overhead. The place names Massah (testing) and Meribah (quarreling) became reminders of this failure (Psalm 95:8-9; Hebrews 3:8). Yet God graciously stands on the rock as Moses strikes it, and water flows. Christians have read this as a picture of Christ, since Paul writes that the rock was Christ (1 Corinthians 10:4), who was struck so that living water could flow to His people (John 7:37-39).
The battle with Amalek is Israel's first war. Joshua, mentioned here for the first time, leads the army, while Moses intercedes on the hill with God's rod. The rise and fall of the battle with Moses' hands teaches that victory comes from God, not merely from military strength.
When Moses grows weary, Aaron and Hur support him, a beautiful picture of shared ministry and prayer. Moses records the event and builds an altar named Yahweh-Nissi, Yahweh our Banner. A banner was a rallying flag in battle. God Himself is the one His people rally around. Christians have read this as a picture of Christ, who always lives to intercede for us (Hebrews 7:25).