Aṭṭhikamahapphalasutta
Sāvatthinidānaṁ. “Aṭṭhikasaññā, bhikkhave, bhāvitā bahulīkatā mahapphalā hoti mahānisaṁsā. Kathaṁ bhāvitā ca, bhikkhave, aṭṭhikasaññā kathaṁ bahulīkatā mahapphalā hoti mahānisaṁsā? Idha, bhikkhave, bhikkhu aṭṭhikasaññāsahagataṁ satisambojjhaṅgaṁ bhāveti vivekanissitaṁ virāganissitaṁ nirodhanissitaṁ vossaggapariṇāmiṁ …pe… aṭṭhikasaññāsahagataṁ upekkhāsambojjhaṅgaṁ bhāveti vivekanissitaṁ virāganissitaṁ nirodhanissitaṁ vossaggapariṇāmiṁ. Evaṁ bhāvitā kho, bhikkhave, aṭṭhikasaññā evaṁ bahulīkatā mahapphalā hoti mahānisaṁsā”ti.
A Skeleton
At Sāvatthī. “Mendicants, when the perception of a skeleton is developed and cultivated it’s very fruitful and beneficial. How so? It’s when a mendicant develops the perception of a skeleton together with the awakening factors of mindfulness, investigation of principles, energy, rapture, tranquility, immersion, and equanimity, which rely on seclusion, fading away, and cessation, and ripen as letting go. That’s how the perception of a skeleton, when developed and cultivated, is very fruitful and beneficial.”