Numbers 21:6-8

6Then the LORD sent venomous snakes among them; they bit the people and many Israelites died.

7The people came to Moses and said, “We sinned when we spoke against the LORD and against you. Pray that the LORD will take the snakes away from us.” So Moses prayed for the people. 8The LORD said to Moses, “Make a snake and put it up on a pole; anyone who is bitten can look at it and live.”