IF by night, Thy devotee unclothed [awakened], with dishevelled hair [mind freed], recites whilst meditating on Thee [the Divine Mother], Thy mantra [sacred word], when with his Śakti [consort] youthful, full-breasted, and heavy-hipped, such an one makes all powers subject to him [because he conquers himself], and dwells on the earth ever a seer [with inner powers].
'Laya Yoga ' [science of dissolution] is here described in this and following verses.
Gheraṇda-Saṁhitā says, 'One should become Śaktimaya by doing Yoni Mudra ["practice of the female sexual organ"]. One should be in Paramātmā [state of elevated Consciousness] with sweet Śṛngārarasa (love sentiment) and being Blissful (Ānandamaya) should unite with Brahman.'
The Gorakṣa-Saṁhitā says, 'Raising the Śakti [energy] with the Jīva [soul] to the Lotus in the head one should become Śaktimaya and uniting with Śiva [the Holy Spirit] should think of all forms of happiness and enjoyment.'
The Tantra-Kalpadruma says, 'One should meditate on Devī Kuṇdalinī as Iṣtadevatā, ever youthful, of the age of sixteen, full-breasted, dark, subtle, appearing as creation and in the form of creation, maintenance and dissolution (Ṣṛṣti-sthiti-layātmikā).'
Whilst in union (Maithuna) the mind must be concentrated on Devī Kāli and japā [mantra repetition] must be done of Her Mahāmantra. The devotee should not think of aught else.
Excerpted from the Vimalānandadāyini Commentary on that Lord of Hymns called the Karpūrādi-Stotra to Śrimad Dakṣiṇa-Kālikā as reproduced in Hymn to Kali, by Arthur Avalon (Sir John George Woodroffe),