This was said by the Blessed One, said by the Arahant, as I have heard:
“Bhikkhus, dwell being virtuous, |accomplished in the moral code of conduct::accomplished in the monastic code of discipline, accomplished in harmonious and pure conduct with others [pātimokkha]|. Dwell restrained by the restraint of this moral code of conduct, mindful of proper behavior and keeping to suitable places, seeing danger even in the slightest faults. Having undertaken this, train in the |training guidelines::the Buddha’s teaching instructions for an individual [sikkhāpada]|.
For those of you, bhikkhus, who dwell being virtuous, accomplished in the moral code of conduct, restrained by the restraint of this moral code of conduct, mindful of proper behavior and keeping to suitable places, seeing danger even in the slightest faults, having undertaken this, training in the training guidelines, what more is there to be done?
If, while walking, bhikkhus, a bhikkhu is free of |craving::greediness, wanting, yearning [abhijjhā]| and |ill will::hatred, hostility, animosity [byāpāda]|, free from |dullness and drowsiness::lack of mental clarity or alertness, mental sluggishness, lethargy, sleepiness lit. stiffness (of mind/body due to tiredness) [thinamiddha]|, free from |restlessness and worry::agitation and edginess, distraction, fidgeting, fiddling, uneasiness [uddhaccakukkucca]|, and has abandoned |doubt::uncertainty, indecisiveness [vicikiccha]|, tireless energy is aroused in him, |unmuddled::without confusion [asammuṭṭha]| |mindfulness::full awareness and recollection of the body, feelings, mind, and mental qualities, observing them clearly with sustained attention, free from craving and distress [sati]| is established, their body is |tranquil::peaceful, calm [santa]|, |without agitation::without arousal, without excitement [asāraddha]|, their mind is |collected::composed, settled [samāhita]| and |unified::one-pointedness, with oneness, integrated, well-composed, concentrated [ekagga]|. Such a bhikkhu is said to be |with continuous effort::ardent, zealous, with energy, with application [ātāpī]|, |with concern::with shame, with regret, having remorse [ottāpī]|, continuously |with energy aroused::with initiative [āraddhavīriya]|, and |determined::resolute, applying oneself [pahitatta]| while walking.
If, while standing, bhikkhus, a bhikkhu is free of craving and ill will, free from dullness and drowsiness, free from restlessness and worry, and has abandoned doubt, tireless energy is aroused in him, unmuddled mindfulness is established, his body is tranquil, without agitation, his mind is collected and unified. While standing, bhikkhus, such a bhikkhu is said to be with continuous effort, with concern, continuously with energy aroused, and determined.
If, while sitting, bhikkhus, a bhikkhu is free of craving and ill will, free from dullness and drowsiness, free from restlessness and worry, and has abandoned doubt, tireless energy is aroused in him, unmuddled mindfulness is established, his body is tranquil, without agitation, his mind is collected and unified. While sitting, bhikkhus, such a bhikkhu is said to be with continuous effort, with concern, continuously with energy aroused, and determined.
If, while lying down and |awake::alert, lucid [jāgara]|, bhikkhus, a bhikkhu is free of craving and ill will, free from dullness and drowsiness, free from restlessness and worry, and has abandoned doubt, tireless energy is aroused in him, unmuddled mindfulness is established, his body is tranquil, without agitation, his mind is collected and unified. While lying down and awake, bhikkhus, such a bhikkhu is said to be with continuous effort, with concern, continuously with energy aroused, and determined.”
The Blessed One spoke on this matter. In this regard, it is said:
“Composed while walking, composed while standing,
composed while sitting, composed while lying down;
Composed while bending back,
and composed while stretching out;
Above, across, and below,
as far as the world extends;
There he carefully contemplates the nature of things,
through the arising and passing away of the aggregates.
Who remains persistent,
with a calm way of being, |unruffled::not agitated, not arrogant, not pompous [anuddhata]|;
Practicing correctly for tranquility of mind,
ever mindful in training;
They call such a bhikkhu,
one who is continuously resolute.”
This matter too was spoken by the Blessed One, as I have heard.