The Yoga Shikha Upanishad probably originated from the 13th century. This extract from the first chapter perhaps present the earliest known tantric view of Hatha yoga and Raja yoga. This Upanishad is also the oldest text in which the two terms are defined.


Raja yoga described as the union of male semen (Retas (रेतस्, Retas)) with female vaginal secretion (Rajas (रजस्, Rajas)) (YSU I.137).This interpretation of Raja yoga was often literally translated particularly in tantric Kaula (कौल, Kaula) schools. In other tantric traditions, Raja-Yoga (रजयोग, Raja-Yoga) is often translated as the union of Shiva (शिव, Śiva) and Shakti (शक्ति, Śakti), the male and female beings.Modern interpretations of the term Raja yoga usually gloss over these tantric ideas.


Sentence 135

tad-aikye sadhite brahmansh-chittam yati vilinatam |"
pavanah sthairyam-ayati laya-yog[a]-{o}[u]daye sati ||135||

तदैक्ये साधिते ब्रह्मंश्चित्तं याति विलीनताम् ।"
पवनः स्थैर्यमायाति लययोग्[अ]{ओ}[उ]दये सति ॥१३५॥

tad-aikye sādhite brahmaṁś-cittaṁ yāti vilīnatām ।"
pavanaḥ sthairyam-āyāti laya-yog[a]-{o}[u]daye sati ॥135॥

When the unity is perfected the changeable (Chitta) in the human being is absorbed in the Absolute (Brahma). |
The goal of Laya-Yoga will be reached through the resulting rest of the life force (Prana). ||135||

tad (तद्, tad) = so, then
aikye (ऐक्ये, aikye) = unity, harmony, equality (Loc.)
sadhita (साधित, sādhita) = achievement, perfection
brahma (ब्रह्म, brahma) = impersonal universal soul, the absolute
chitta (चित्त, citta) = all changeable in the human being, spirit
yati (याति, yāti) = achieve
vilina (विलीन, vilīna) = dissolved in, absorbed in, melted, disappeared
pavanah (पवनः, pavanaḥ) = life force, breath, Prana
sthairyam (स्थैर्यम्, sthairyam) = firmness, stability, rigidness, rest
ayati (आयाति, āyāti) = reach, arrive
laya (लय, laya) = Laya, synonym for Samadhi, the goal of Yoga, dissolving,
yoga (योग, yoga) = Yoga
udaya (उदय, udaya) = result, conclusion, product, consequence
sati (सति, sati) = sati (साति, sāti) = achieve, become