Numbers 21:12 (KJV)

Therefore the people came to Moses, and said, We have sinned, for we have spoken against the LORD, and against thee; pray unto the LORD, that he take away the serpents from us. And Moses prayed for the people.

And the LORD said unto Moses, Make thee a fiery serpent, and set it upon a pole: and it shall come to pass, that every one that is bitten, when he looketh upon it, shall live.

And Moses made a serpent of brass, and put it upon a pole, and it came to pass, that if a serpent had bitten any man, when he beheld the serpent of brass, he lived.

And the children of Israel set forward, and pitched in Oboth.

And they journeyed from Oboth, and pitched at Ijeabarim, in the wilderness which is before Moab, toward the sunrising.

From thence they removed, and pitched on the other side of Arnon, which is in the wilderness that cometh out of the coasts of the Amorites: for Arnon is the border of Moab, between Moab and the Amorites.

Wherefore it is said in the book of the wars of the LORD, What he did in the Red sea, and in the brooks of Arnon,

And at the stream of the brooks that goeth down to the dwelling of Ar, and lieth upon the border of Moab.

And from thence they went to Beer: that is the well whereof the LORD spake unto Moses, Gather the people together, and I will give them water.

Then Israel sang this song, Spring up, O well; sing ye unto it: