The Book of Zohar, “Tzav” (Command), Item 50: “A perpetual fire shall burn on the altar; it shall not go out.” This is the Torah, which is called “fire.” It was said about it, “‘Is not My word like fire’ declares the Lord?” meaning that it should always shine on the altar, on Malchut.“
An illumination of the first nine Sefirot of the Partzuf depends on the presence of the Direct Light and the Returning Light in them, while Malchut should constantly nourish them like a candle.
If we take an oil lamp and oil, they will not light separately. But if we connect them, the oil fuels the lamp and burns.
This state symbolizes the attribute of the ten Sefirot. Nine Sefirot is the oil lamp itself, different types of the intention of in order to bestow, and the matter that burns is Malchut, although it cannot burn by itself.
Therefore the correct connection of Malchut, which nourishes the first nine Sefirot, provides them with constant Light.
From KabTV’s “Secrets of the Eternal Book” 11/27/13