[97] "Brahmin, when a bhikkhu knows moderation in eating, the Tathāgata trains him further: 'Come, bhikkhu, dwell devoted to wakefulness. During the day, purify the mind (citta) of obstructive states (āvaraṇīyā dhammā) by walking meditation and by sitting. In the first watch of the night, purify the mind of obstructive states by walking meditation and by sitting. In the middle watch of the night, you should lie down in the lion's posture (sīhaseyyā) on the right side, placing one foot upon the other, with mindfulness and clear comprehension, having attended to the perception of rising (uṭṭhānasaññā). In the last watch of the night, having risen, purify the mind of obstructive states by walking meditation and by sitting.'"
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.