Numbers 21:6-9

So the LORD sent them poisonous snakes; they bit the people, and many of the Israelites died. The people came to Moses and said, “We sinned when we grumbled at you and the LORD. Pray that the LORD will take away these snakes.” So Moses prayed for the people. The LORD said to Moses, “Make a bronze snake, and put it on a pole. When anyone who is bitten looks at it, that person will live.” So Moses made a bronze snake and put it on a pole. Then when a snake bit anyone, that person looked at the bronze snake and lived.