Ānāpānasati Sutta
The Ānāpānasati Sutta (Pāli) or Ānāpānasmṛti Sūtra (Sanskrit), "Breath-Mindfulness Discourse," Majjhima Nikaya 118, is a discourse that details the Buddha's instruction on using awareness of the breath (anapana) as an initial focus for meditation. The sutta includes sixteen steps of practice, and groups them into four tetrads, associating them with the four satipatthanas (placings of mindfulness).