Zohar 1:83a-b

Jewish Mysticism
“With my breath [I have longed for you at night],” in order to pursue after you and not to be tempted astray by any foreign kind. Come and see. “My breath,” this is the breath that has dominion at night to pursue after its level. The spirit [has dominion] during the day, as it is written, “with my soul I have desired you at night,” this is the soul that has dominion at night, “with my spirit within me I seek you,” this is the spirit which has dominion during the day. And if you think that these are two levels separated from one another, it is not so, for they are one level, and they are two in one combination, and there is another supernal one that has dominion over them and cleaves to them and they are within it, and it is called soul [neshamah], and all of these levels ascend into the secret of wisdom, for when one gazes into these levels, such a man gazes into the supernal wisdom. And this soul ascends into them and they cleave to it, and when it has dominion, then such a man is called “holy,” “completed of all,” a single desire towards the Holy One, Blessed be He. Breath [nefesh] is the lower arousal, as it is coextensive with the body and it nourishes it, and the body is united with it, and it is united with the body. Afterwards, a throne is adorned and made for the spirit to dwell upon in the arousal of this breath that is united with the body, as it is written, “until He pours forth a spirit upon us from on high” (Isaiah 32-15). And after both [the breath and the spirit] are adorned, they are ready to receive the soul, for the spirit is made to be a throne for the soul to dwell upon, and this soul is hidden, supernal above all, concealed of all concealed. There is a throne for a throne, and a throne for that which is elevated above it, and when one gazes into the levels, one finds the mystery of wisdom in this matter [milah], and all is wisdom, to cleave in this manner to concealed matters. Come and see. Breath is the lower arousal that cleaves to the body. [This can be understood] in the manner of the flame of a candle, for the lower flame, which is black, adheres to the wick, and it does not separate from it and it is adorned only in it. When it is adorned in the wick, it becomes a throne for the white light above it which dwells upon the black light. Then, when both of them are adorned, the white light becomes a throne for a concealed light that is not seen and not known which dwells upon the white light; and thus, a complete light. Such it is with man, for he is perfected of all, and for this reason he is called Holy, as it is said “to the holy ones that are upon the earth…” (Ps. 16-3). In this manner is the upper mystery.

Translated by Hartley Lachter