P. 217. (5th perek). Torah is called the mazon hanefesh (food of the soul). The neshama's food is dveykus (bonding) with Hashem. Just like food becomes one with the body when eaten, so too, the Or Eloki (G-dly light) becomes one with the neshama when it learns Torah. A person should be able to properly digest the Torah that he is learning. The Arizal says that in the Garden of Eden, the clothing of the neshama are the mitzvos that we did and the food of the neshama is the Torah we learned. It is very important to limit our consumption of the physical so as not to dull our sensitivity to the spiritual.