An ubiquitous symbol throughout world religions and mythology, which always has one of two primary meanings. The serpent or snake represents either a negative intelligence (cunning) or a positive intelligence (wisdom). There are far too many examples to cite here, but significant ones include the Biblical serpent of Eden; the Bronze Serpent of Moses; the Greek serpent of the Hesperides and the dreaded Python; the Buddhist serpent that protected the Buddha; and the Egyptian serpents (both positive and negative).
“Lo and behold, since Esau followed on the serpent, Jacob dealt with him slyly, as the serpent was cunning and had crooked ways. As it is written, "the serpent was more cunning than any beast” (Genesis 3:1), which means that Esau was cunning and sly (Genesis 25: 27: “And the boys grew: and Esau was a cunning hunter”). Yet, what Jacob did with Esau was serpent-like. This was as it ought to have been; by making Esau go after that serpent, so that he would be separated from Jacob, and thus share nothing with him in this world or in the world to come.” —Zohar
"Dan shall be a serpent by the way, an adder in the path, that biteth the horse heels, so that his rider shall fall backward. I have waited for thy salvation, Oh Iod-Havah." —Genesis: 49:17,18
"And Iod-Havah 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." —Numbers 21:8, 9
"Jesus said: “Behold, I send you forth as sheep in the midst of wolves: be ye therefore wise as serpents, and harmless as doves.”—Matthew 10:16