The Long Āgama Sūtra 2.72-73

2.72

爾時，世尊遙見五百隷車，車馬數萬，填道而來，告諸比丘：「汝等欲知忉利諸天遊戲園觀，威儀容飾，與此無異。汝等比丘！當自攝心，具諸威儀。云何比丘自攝其心？於是比丘內身身觀，精勤不懈，憶念不忘，捨世貪憂；外身身觀，精勤不懈，憶念不忘，捨世貪憂；內外身觀，精勤不懈，捨世貪憂。受、意、法觀，亦復如是。云何比丘具諸威儀？於是比丘可行知行，可止知止，左右顧視，屈伸俯仰，攝持衣鉢，食飲湯藥，不失宜則，善設方便，除去蔭蓋，行住坐臥，覺寤語默，攝心不亂，是謂比丘具諸威儀。」

At that time, the Bhagavat saw from afar the five hundred Licchavis coming, filling the road with tens of thousands of carriages and horses. He told the bhikṣus: “If you wish to know how the devas of the Trāyastriṃśa heaven sporting in their pleasure gardens appear in deportment and adornment, they are no different from this. Bhikṣus! You should collect your minds and be complete in all deportment. How does a bhikṣu collect his mind? Here, a bhikṣu contemplates the body internally as body, ardent, unflagging, mindful and unforgetting, putting away worldly covetousness and distress; he contemplates the body externally as body, ardent, unflagging, mindful and unforgetting, putting away worldly covetousness and distress; he contemplates the body internally and externally as body, ardent, unflagging, putting away worldly covetousness and distress. Contemplation of feelings, of mind, and of phenomena is likewise. How is a bhikṣu complete in all deportment? Here, a bhikṣu knows when to walk when walking is appropriate; knows when to halt when halting is appropriate; looks to the left and right; bends, extends, lowers, and raises [his limbs]; properly bears his robes and bowl; takes food, drink, and medicine without departing from proper measure; skillfully employs expedient means to remove hindrances; and whether walking, standing, sitting, or lying down, awake, asleep, speaking, or silent, he collects his mind without distraction. This is called a bhikṣu complete in all deportment.”

The Bhagavān saw those 500 Licchavi chariots from afar, their horses were so numerous, filling the road as they approached. He told the monks, “If you want to know how dignified-looking and decorated the Trāyastriṃśa gods are when they entertain themselves in their scenic parks, it’s no different than this.

“You monks, you should collect your thoughts and behave in a dignified manner. How does a monk collect his thoughts? Here, a monk observes body internally to be body. Diligent and unflagging, he’s mindful and doesn’t forget it, setting aside worldly greed and sorrow. He observes body externally to be body. Diligent and unflagging, he’s mindful and doesn’t forget it, setting aside worldly greed and sorrow. He observes body internally and externally to be body. Diligent and unflagging, he’s mindful and doesn’t forget it, setting aside worldly greed and sorrow. He also observes feelings, mind, and principles in the same way.

“How does a monk behave in a dignified manner? Here, a monk knows to walk when he should walk and to stop when he should stop. He looks left and right before bending and stretching, looking down and up, or gathering his robes and bowl. When he eats, drinks, and takes medicine, he doesn’t forget what’s appropriate. He skillfully prepares when relieving himself, taking away screens, while walking, standing, sitting, and lying down, and while awake, asleep, speaking, and being quiet. He collects his thoughts and isn’t disturbed. This is a monk who behaves in a dignified manner.”

2.73

爾時，五百隷車往至菴婆婆梨園，欲到佛所，下車步進，頭面禮足，却坐一面。如來在座，光相獨顯，蔽諸大眾，譬如秋月，又如天地清明，淨無塵翳，日在虛空，光明獨照。爾時，五百隷車圍遶侍坐，佛於眾中，光相獨明。是時，坐中有一梵志名曰并𩞚，即從座起，偏袒右臂，右膝著地，叉手向佛，以偈讚曰：

Then the five hundred Licchavis arrived at Āmrapālī’s grove. Wishing to go to the Buddha's place, they stepped down from their carriages, walked forward, bowed their heads at his feet, and sat to one side. As the Tathāgata sat upon his seat, the signs of his light stood out alone, outshining the great assembly, just like the autumn moon, or like the clear and bright sky and earth, pure and free of dust and mist, when the sun hangs in the open air, shining brightly alone. At that time, the five hundred Licchavis sat surrounding and attending upon him, and among the assembly, the Buddha’s marks and light alone shone brightly. At that moment, there was among those seated a brahmacārin named Piṅgika, who rose from his seat, bared his right shoulder, knelt with his right knee to the ground, joined his palms toward the Buddha, and praised him in verse: