[751] **"Ardent, one should devote oneself to wakefulness" (jāgariyaṃ bhajeyya ātāpī):** here a bhikkhu, during the day, should purify the mind (citta) from obstructive states (āvaraṇīyā dhammā) by walking meditation and by sitting; in the first watch of the night he should purify the mind from obstructive states by walking meditation and by sitting; in the middle watch of the night he should lie down in the lion's posture (sīhaseyyā) on his right side, placing one foot upon the other, with mindfulness and clear comprehension, having attended to the perception of rising; in the last watch of the night, having risen, he should purify the mind from obstructive states by walking meditation and by sitting.
**"Should devote oneself to wakefulness":** he should devote himself to, devote himself fully to, and practice wakefulness (jāgariyā) — hence, "should devote oneself to wakefulness."
**"Ardent" (ātāpī):** "ardor" is a designation for energy (vīriya) — that mental instigation of energy, striving, endeavor, exertion, effort, zeal, enthusiasm, vigor, steadfastness, unfaltering endeavor, not relinquishing desire, not relinquishing the task, firm upholding of the task, energy, the faculty of energy, the power of energy, right effort. One who is possessed of, fully possessed of, come to, fully come to, endowed with, fully endowed with, and furnished with this ardor — he is called "ardent." Hence, "ardent, one should devote oneself to wakefulness."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.