all breathing. Others, curtailing the eating process, offer the outgoing breath into itself as a sacrifice."

Yoga Sutras of Patanjali

Pranayama is the fourth "limb" of the eight limbs of Ashtanga Yoga, as mentioned in verse 2.29 of the Yoga Sutras of Patanjali. Patanjali, a Rishi, discusses his specific approach to pranayama in verses 2.49 through 2.51,