Although they are very similar, there are nevertheless several appreciable differences between the Torah – “light”- and the mitzva, the “lamp” or the “flame.” The Torah is permanent. You can turn off a lamp or a flame, but you cannot turn off light. The existence of a mitzva is man’s doing. Someone can choose to “light” or not “light” a mitzva. In contrast, the existence of the Torah does not depend on anyone. One of the main themes in Jewish mysticism is that there was a primordial light, the light of En Sof, through which one could see from one end of the universe to the other. This is the light. This light was too strong for men, and the Sages tell us that, “God hid the light and concealed it for the righteous in the end of days.”* This is why we receive partial light, the light of the sun and the moon, and not total light.
“Where did God hide this light?” asked the founder of Ḥasidism, the Ba’al Shem Tov, and answered: “In the Torah!”
From The Seven Lights, pg 333.