Śivasaṃhitā 4.6

After the ascent through the three liṅgas and the absorption of nectar at each cakra, the verse prescribes the return: consciousness must descend back to the kula —the perineal space, center of primordial energy— and this return can only be accomplished through mātrāyoga. The exclusivity of the method (“in no other way,” nānyathā) underscores its technical and irreplaceable character.

Kula designates in Tantra the sacred perineal space but also “family” or “lineage,” evoking belonging to an initiatic tradition. Mātrāyoga is the yoga of mātrās, the metric units of prāṇāyāma: the precise regulation of the durations of inhalation, retention, and exhalation. The term mātrā also means “measure,” indicating that the return demands rhythmic precision.

This verse introduces the principle of circularity that characterizes the complete yonimudrā: ascent and descent form a closed cycle. There is no liberation that abandons the body; energy rises, transforms, and returns, enriched, to its point of origin. This is the distinguishing feature between Tantra and systems of pure renunciation.