Tanya Chapter 35 part 2

King Solomon taught, “a wise man’s eyes are in his head.” But isn’t that where every person’s eyes are? The wise man stands out in that his eyes are focused on the Shechina that rests upon his head, mindful to supply oil for the light. Just as physically, there needs to be oil to fuel a wick and sustain a fire, so too spiritually: The body is only the wick, and to fuel the light of the Shechina, there needs to be oil, which are mitzvos and good deeds. Why can’t the Divine soul serve as the oil for the Shechina? Because even the soul of the loftiest tzadik has a separate consciousness, an identity of its own, lacking the utter nullification necessary to be totally absorbed with the flame, the light of the Shechina.