Now the serpent was more (a) subtil than any beast of the field which the LORD God had made. And he (b) said unto the woman, Yea, hath God said, Ye shall not eat of every tree of the garden?
(a) As Satan can change himself into an angel of light, so did he abuse the wisdom of the serpent to deceive man.
(b) God allowed Satan to make the serpent his instrument and to speak through him.