Numbers 21:4–9 describes an event where the Israelites complained against God and Moses. They were unhappy about the food and water and said, "We detest this wretched food!" (21:5). In response, the Lord sent poisonous snakes that bit and killed many people (see Deuteronomy 8:15). Realizing their mistake, the Israelites asked Moses to pray for the removal of the snakes. God told Moses to make a bronze snake. Anyone bitten could look at it and God would heal them (Numbers 21:8).
This was not a typical medical treatment. The healing came from God and required faith to look at the bronze snake and trust in God's healing power. The snake bites were a result of God's punishment. But he also provided a way for their salvation through his mercy (see Wisdom of Solomon 16:5–7).
When Hezekiah became king of Judah in 715 BC, the Israelites started using Moses' bronze serpent as an idol (see 2 Kings 18:1–4). They probably kept the image to remember God's power. This was similar to other holy things from the wilderness period (see Deuteronomy 10:5; Hebrews 9:4–5). Yet, they began worshiping it as another god. So they had to destroy it like other pagan worship items and pillars. Such idolatry threatens the worship of the one true God (compare Exodus 32).
Jesus mentioned the bronze snake incident to prophesy how he would die. He would "be lifted up" on the cross like Moses lifted the snake on a pole (John 3:14–15; see also 8:28; 12:32–33). The metal snake image acted as a cure for snake bites. Similarly, those who look to Christ's cross and accept Jesus' sacrifice receive an eternal promise (John 3:14–16).
The Lord sent snakes to punish Israel for complaining about the manna in the wilderness (Numbers 21:4–9). Jesus called himself "the true bread from heaven," the spiritual manna that gives eternal life to his people (John 6:32–40).
Passages for Further Study
Numbers 21:4–9; 2 Kings 18:1–4; John 3:14–15; 6:32–40; 8:28; 12:30–34