Thus have I heard. At one time, the Buddha was abiding in Śrāvastī, in the Jeta Grove, in Anāthapiṇḍada’s Park.
At that time, the Bhagavān said to the bhikṣus, “You should cultivate mindfulness of breathing. A bhikṣu who cultivates mindfulness of breathing, cultivating it assiduously, obtains rest in body and rest in mind, with vitarka and vicāra, with extinction and purity, connected with knowledge cultivated to completion.”
After the Buddha had spoken this sūtra, the bhikṣus heard what the Buddha had said, and joyfully practiced in accordance.