Numbers 21:7-9

21:7 Then the people came to Moses and said, “We have sinned, for we have spoken against the Lord and against you. Pray to the Lord that he would take away the snakes from us.” So Moses prayed for the people.

21:8 The Lord said to Moses, “Make a poisonous snake and set it on a pole. When anyone who is bitten looks at it, he will live.” 21:9 So Moses made a bronze snake and put it on a pole, so that if a snake had bitten someone, when he looked at the bronze snake he lived.

Numbers 21:2

21:2 So Israel made a vow to the Lord and said, “If you will indeed deliver this people into our hand, then we will utterly destroy their cities.”

Numbers 18:4

18:4 They must join with you, and they will be responsible for the care of the tent of meeting, for all the service of the tent, but no unauthorized person may approach you.