A FingernailNakhasikhasutta

At Sāvatthī.Sāvatthiyaṁ viharati.

Then the Buddha, picking up a little bit of dirt on his fingernail, addressed the mendicants:Atha kho bhagavā parittaṁ nakhasikhāyaṁ paṁsuṁ āropetvā bhikkhū āmantesi: “What do you think, mendicants?“Taṁ kiṁ maññatha, bhikkhave, Which is more: the little bit of dirt on my fingernail, or this great earth?”katamaṁ nu kho bahutaraṁ, yo cāyaṁ mayā paritto nakhasikhāyaṁ paṁsu āropito yā cāyaṁ mahāpathavī”ti?

“Sir, the great earth is far more.“Etadeva, bhante, bahutaraṁ yadidaṁ mahāpathavī. The little bit of dirt on your fingernail is tiny.Appamattakoyaṁ bhagavatā paritto nakhasikhāyaṁ paṁsu āropito. Compared to the great earth, it doesn’t count, there’s no comparison, it’s not worth a fraction.”Saṅkhampi na upeti upanidhimpi na upeti kalabhāgampi na upeti mahāpathaviṁ upanidhāya bhagavatā paritto nakhasikhāyaṁ paṁsu āropito”ti.

“In the same way the sentient beings reborn as humans are few,“Evameva kho, bhikkhave, appakā te sattā ye manussesu paccājāyanti; while those not reborn as humans are many.atha kho eteyeva bahutarā sattā ye aññatra manussehi paccājāyanti.

So you should train like this:Tasmātiha, bhikkhave, evaṁ sikkhitabbaṁ: ‘We will stay diligent.’‘appamattā viharissāmā’ti. That’s how you should train.”Evañhi vo, bhikkhave, sikkhitabban”ti.