Amaraugha
[2] Jason Birch comments that the Amaraugha seems to have modified a Buddhist method to create a technique "for moving kuṇḍalinī and attaining a Śaiva form of Rājayoga."[2] If it was indeed written at Kadri, just at the time when Buddhist groups were switching to Śaivism, he writes, then the text captures the moment that both haṭha and rāja yoga take shape as Śaiva and Vajrayāna siddha traditions collide.[11][12] Birch notes that much of the content is shared between the two recensions, Amaraugha and Amaraughaprabodha, but that the latter adds an assortment of materials including verses from other texts.[15] The Amaraugha says that Vajroli is attained, presumably with samādhi, when the mind has become pure and the sushumna nadi, the central channel of the subtle body, has been unblocked to allow breath to flow freely.[15] Birch comments that the Amaraugha's haṭha yoga indicates a change from the older view that its method consisted of forcing generative fluids upwards, to getting kuṇḍalinī to move.