Numbers 21:8-9

Amplified Bible

⁸ 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.” ⁹ 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.