"The verse The mitzvah is a lamp (or: flame) and the Torah, light (Proverbs 6:23) distinguishes between Torah and Mitzvah.
On the first day of Creation God created primordial light, through which one could see from one end of the universe to the other.
This light was too strong for man, and the Sages tell us (Babylonian Talmud, Hagigah 12a) that God hid the light and concealed it for the righteous in the end of days.
The Ba'al Shem Tov, the founder of Hasidism, asks: "Where did God hide this light?”
And he answers: 'In the Torah.'
Thus, whoever perceives the essence of the Torah perceives the total light of the Infinite.
This is the basic difference between the Torah and the mitzvah:
The Torah reflects the Infinite light, whereas the mitzvah sheds light on a specific object in a specific situation.
As such, the mitzvah has an advantage over the Torah:
While the Torah, however beautiful, is distant, the mitzvah is close to us, it is a lamp that one can hold and move.
Indeed, in another verse, the soul is compared to a lamp which helps us see details better: The soul of man is the lamp of God, revealing all his inmost parts (Proverbs 20:27).
--Rabbi Adin Steinsaltz
From an essay "Man of Light" by Rabbi Adin Steinsaltz