Numbers 21:2-6

So Israel made a vow to the Lord and said, “If You will indeed hand over this people to me, then I will utterly destroy their cities.”

The Lord heard the voice of Israel and turned over the Canaanites; then they utterly destroyed them and their cities. And the place was named Hormah.

Then they set out from Mount Hor by the way of the Red Sea, to go around the land of Edom; and the people became impatient because of the journey.

So the people spoke against God and Moses: “Why have you brought us up from Egypt to die in the wilderness? For there is no food and no water, and we are disgusted with this miserable food.” The Bronze Serpent

Then the Lord sent fiery serpents among the people and they bit the people, so that many people of Israel died.