The Ascent of Mount CarmelChapter XV. Explanation of the last lines

from this slavery and subjection, that is, unimpeded and unembarrassed by all its desires. To effect this, it was advantageous for the soul to have departed in the dark night, in the denial of every pleasure, and in the mortification of every desire.

2. “My house being now at rest,’ that is, the sensual part of the soul, the house of the desires being now at rest, because those desires are overcome and lulled to sleep. For until the desires be lulled to sleep by the mortification of sensuality, and sensuality itself be mortified in them, so that it shall be contrary to the spirit no more, the soul cannot go forth in perfect liberty to the fruition or the union with the Beloved.