(Hebrew נחש) Literally, "serpent." A very deep and multifaceted symbol in the Judeo-Christian scriptures, whose meaning is revealed in Kabbalah. Nahasch, meaning “serpent” and “a shining one,” comes from the root "to shine." In Chaldee it means brass, because of its shine.
"Now the nachash was more subtil than any beast of the field which the LORD God had made. And he said unto the woman, Yea, hath God said, Ye shall not eat of every tree of the garden?" - Gen 3:1
"And he said, Cast it on the ground. And he cast it on the ground, and it became a nahasch; and Moses fled from before it." - Ex 4:3
"And Moses made a serpent (nachash) 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." - Numbers 21