Numbers 21:8-9

⁸Then the Lord said to Moses, “Make a fiery serpent, and set it on a standard; and it shall come about, that everyone who is bitten, when he looks at it, he will live.” ⁹And Moses made a bronze serpent and set it on the standard; and it came about, that if a serpent bit any man, when he looked to the bronze serpent, he lived.