Numbers 21:5-7

21:5 And the people spoke against God and against Moses, “Why have you brought us up out of Egypt to die in the wilderness, for there is no bread or water, and we detest this worthless food.”

21:6 So the Lord sent poisonous snakes among the people, and they bit the people; many people of Israel died. 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.