Navaṅguposathasutta
“Navahi, bhikkhave, aṅgehi samannāgato uposatho upavuttho mahapphalo hoti mahānisaṁso mahājutiko mahāvipphāro. Kathaṁ upavuttho ca, bhikkhave, navahaṅgehi samannāgato uposatho mahapphalo hoti mahānisaṁso mahājutiko mahāvipphāro? Idha, bhikkhave, ariyasāvako iti paṭisañcikkhati: ‘yāvajīvaṁ arahanto pāṇātipātaṁ pahāya pāṇātipātā paṭiviratā nihitadaṇḍā nihitasatthā lajjī dayāpannā sabbapāṇabhūtahitānukampino viharanti; ahampajja imañca rattiṁ imañca divasaṁ pāṇātipātaṁ pahāya pāṇātipātā paṭivirato nihitadaṇḍo nihitasattho lajjī dayāpanno sabbapāṇabhūtahitānukampī viharāmi. Imināpaṅgena arahataṁ anukaromi; uposatho ca me upavuttho bhavissatī’ti. Iminā paṭhamena aṅgena samannāgato hoti …pe….
The Sabbath with Nine Factors
“Mendicants, the observance of the sabbath with its nine factors is very fruitful and beneficial and brilliant and bountiful. And how should it be observed? It’s when a noble disciple reflects: ‘As long as they live, the perfected ones give up killing living creatures, renouncing the rod and the sword. They are scrupulous and kind, and live full of sympathy for all living beings. I, too, for this day and night will give up killing living creatures, renouncing the rod and the sword. I’ll be scrupulous and kind, and live full of sympathy for all living beings. I will observe the sabbath by doing as the perfected ones do in this respect.’ This is its first factor. …