From:
Theravāda Vinaya Theravāda Collection on Monastic Law
Mahāvibhaṅga The Great Analysis
Sekhiyakaṇḍa The chapter on training
Ujjagghikavagga The subchapter on laughing loudly
18. Dutiyabāhuppacālakasikkhāpada 18. The second training rule on swinging the arms
Tena samayena buddho bhagavā sāvatthiyaṁ viharati jetavane anāthapiṇḍikassa ārāme. At one time the Buddha was staying at Sāvatthī in the Jeta Grove, Anāthapiṇḍika’s Monastery.
Tena kho pana samayena chabbaggiyā bhikkhū bāhuppacālakaṁ antaraghare nisīdanti bāhuṁ olambentā …pe…. At that time the monks from the group of six were swinging and dangling their arms while sitting in inhabited areas. …
“Na bāhuppacālakaṁ antaraghare nisīdissāmīti sikkhā karaṇīyā”ti. “‘I will not swing my arms while sitting in inhabited areas,’ this is how you should train.”
Na bāhuppacālakaṁ antaraghare nisīditabbaṁ. One should not swing one’s arms while sitting in an inhabited area;
Bāhuṁ paggahetvā nisīditabbaṁ. one should sit keeping one’s arms steady.
Yo anādariyaṁ paṭicca bāhuppacālakaṁ antaraghare nisīdati bāhuṁ olambento, āpatti dukkaṭassa. If a monk, out of disrespect, swings and dangles his arms while sitting in an inhabited area, he commits an offense of wrong conduct.
Anāpatti—There is no offense:
asañcicca, if it is unintentional;
assatiyā, if he is not mindful;
ajānantassa, if he does not know;
gilānassa, if he is sick;
vāsūpagatassa, if he has entered his dwelling;
āpadāsu, if there is an emergency;
ummattakassa, if he is insane;
ādikammikassāti. if he is the first offender.
Aṭṭhamasikkhāpadaṁ niṭṭhitaṁ. The eighth training rule is finished.