The Dattātreyayogaśāstra (DYŚ) is one of those texts that changes how we see the history of yoga. Composed in South India around 1200 CE, it is the earliest known work to call a physical yogic system Haṭhayoga and the first to weave that system together with Patañjali’s eight-limbed path. The text unfolds as a conversation between the sage Sāṃkṛti and Dattātreya, a divine yogi revered in the...