Numbers 21:5-9

So the people spoke against God and against Moses, “Why have you brought us out of Egypt to die in the wilderness? For there is no bread, nor is there any water, and we loathe this miserable food.” Then the LORD sent fiery (burning) serpents among the people; and they bit the people, and many Israelites died. So the people came to Moses, and said, “We have sinned, for we have spoken against the LORD and against you; pray to the LORD, so that He will remove the serpents from us.” So Moses prayed for the people. Then the LORD said to Moses, “Make a fiery serpent [of bronze] and set it on a pole; and everyone who is bitten will live when he looks at it.” So Moses made a serpent of bronze and put it on the pole, and it happened that if a serpent had bitten any man, when he looked to the bronze serpent, he lived.