Amrithabindhu Upanishad

It is one of the five Bindu Upanishads, attached to the Atharvaveda, and one of twenty Yoga Upanishads in the four Vedas. The text is notable for condemning "bookish learning" and emphasizing practice, as well as for presenting a six limbed Yoga system which match five stages of the eight stage Patanjali's Yogasutras and offering a unique, different sixth stage. The Amritabindu Upanishad states that there are six limbs of yoga, whose sequence and one limb is different from Patanjali's Yogasutras: 1. Pratyahara: the withdrawal of mind and sensory organs from external objects, and redirecting them to introspection. 2. Dhyanam: meditation. 3. Pranayama: breathing exercises consisting of Rechaka (exhaling completely), Paraka (inhaling deeply) and Kumbhaka (retaining breath for various intervals). 4. Dharana: concentrated introspection on Atman (soul, self) with one's mind. 5. Tarka: reflecting and inner reasoning between one's mind and soul. This is missing in the Yogasutras. 6. Samadhi: communion with and in one's soul.