Dhammapada · 9.6

Māvamaññetha pāpassa, na maṃ taṃ āgamissati;Udabindunipātena, udakumbhopi pūrati;Bālo pūrati pāpassa, thokaṃ thokampi ācinaṃ.

Mavamannetha papassa, na mam tam agamissati; Udabindunipatena, udakumbhopi purati; Balo purati papassa, thokam thokampi acinam.

Do not think lightly of evil, saying 'it will not come to me.' Drop by falling drop, even a water-jar fills. The fool fills with evil, gathering it little by little.

— Dhammapada 9.6

Source: Pali text from the Khuddaka Nikāya of the Pali Canon (oldest extant Buddhist scripture, compiled c. 3rd century BCE). Public-domain English readings drawn from F. Max Müller's translation in Sacred Books of the East, Vol X (1881) and the Buddhist Publication Society's freely-licensed Acharya Buddharakkhita rendering.