Numbers 21:3-6

³And the Lord heard the prayers of Israel, and delivered up the Chanaanite, and they cut them off and destroyed their cities: and they called the name of that place Horma, that is to say, Anathema.

⁴And they marched from mount Hor, by the way that leadeth to the Red Sea, to compass the land of Edom. And the people began to be weary of their journey and labour:

⁵And speaking against God and Moses, they said: Why didst thou bring us out of Egypt, to die in the wilderness? There is no bread, nor have we any waters: our soul now loatheth this very light food.

⁶Wherefore the Lord sent among the people fiery serpents, which bit them and killed many of them.