God's miraculous provision for Israel in the wilderness, and a typological picture of Christ. Exodus 17:1-7 and Numbers 20:7-13 record two occasions when the LORD brought water from a rock to sustain His thirsty people. Psalm 78:20: he smote the rock, that the waters gushed out, and the streams overflowed. Paul interprets the rock typologically in 1 Corinthians 10:4: they drank of that spiritual Rock that followed them: and that Rock was Christ. The pattern is rich: the rock smitten gives life-giving water; Christ smitten on the cross pours out the Spirit (John 7:37-39) and the blood-and-water of His side (John 19:34). Moses' second failure (striking the rock when commanded to speak to it, Num 20) cost him entry into the land — the typological reason being that Christ is smitten once, not twice.