The Anapanasati Sutta (Pāli: Breath-Mindfulness Discourse) is contained in the Majjhima Nikaya as sutta number 118. The sutta details the Buddha's instruction on using the breath as a focus for meditation and is a major text in the Pali Canon of Theravada Buddhism. The sutta lists the 16 objects on which one may meditate in order to bear insight and understanding into the Four Foundations of Mindfulness (Satipaṭṭhāna), the Seven Factors of Awakening (Bojjhangas), and ultimately Nibbana.
See more at Wikipedia.org...