Satan, in the form of a serpent, intends to corrupt what God has created as good. He posed a question in Genesis 3:1, intending to bring doubt in the mind of Eve. This is what unfolded next.
And the woman said unto the serpent, We may eat of the fruit of the trees of the garden: But of the fruit of the tree which is in the midst of the garden, God hath said, Ye shall not eat of it, neither shall ye touch it, lest ye die. And the serpent said unto the woman, Ye shall not surely die: For God doth know that in the day ye eat thereof, then your eyes shall be opened, and ye shall be as gods, knowing good and evil. And when the woman saw that the tree was good for food, and that it was pleasant to the eyes, and a tree to be desired to make one wise, she took of the fruit thereof, and did eat, and gave also unto her husband with her; and he did eat. (Genesis 3:2-6)
In Genesis 2:16-17, God commanded Adam to not eat of the tree of the knowledge of good and evil. However, Eve adds another restriction. She states that they were not to touch it. There are three general reasons given as to why she added this: (1) God gave the restriction, but for His own purposes didn’t reveal it in Scripture, (2) Adam gave Eve the additional restriction, perhaps to further protect her, or (3) Eve added the restriction herself. We don’t know for sure which is true, but regardless, it served to emphasize that the tree of the knowledge of good and evil was off limits.