(Haṭha Yoga Pradīpikā): “Light on Hatha Yoga,” a yogic scripture likely written in the fifteenth century by the great yogi Svatmarama. It is one of the three classic texts of Hatha Yoga (along with the Gheranda Samhita and the Shiva Samhita). This treatise explains the physical practice of many essential yogic techniques and presents the more refined spiritual practices of Raja Yoga. It also describes the practice of Laya Yoga (meditative absorption) via nada anusandhana (the awareness of the inner sound).