Not a word about not touching it, yet when Eve tells the story to the serpent she says, “God said not to eat it or touch it” (Gen. 3:3).
Who added to God’s original command the prohibition of touching the tree – Eve (as explained by the Midrash) or Adam himself (the view of Avot D’Rabbi Natan)?
Whoever it was the effect is the same. It puzzles us because God obviously knew what He wanted and presumably did not expect anyone to attempt to improve upon His orders.
What seems to have happened is that – in the sense in which Pir’kei Avot (chapter 1) uses the words – the first human beings made a fence around the Torah.
Fences protect the property itself. If your way is blocked by a fence it will make it harder to break into the house.
In relation to the mitzvot, adding a protective measure ensures that we do not infringe the actual mitzvah.
Each week we add a few minutes to Shabbat at each end of the day for the same purpose, in order to protect Shabbat itself from an even inadvertent act of trespass.
Here the emphatic Divine command is not to eat the fruit; the “fence” of not even touching the tree helps to make certain that the command itself will be obeyed.