Numbers 21:5-8

and grumbled at God and Moses. They said, “Why did you bring us out of Egypt to die in this desert? There is no bread and no water, and we hate this terrible food!” 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.”