Dhammapada · 25.12
Jhāya bhikkhu mā pamādo, mā te kāmaguṇe ramessu cittaṃ;Mā lohaguḷaṃ gilī pamatto, mā kandi 'dukkhamidan'ti ḍayhamāno.
Jhaya bhikkhu ma pamado, ma te kamagune ramessu cittam; Ma lohagulam gili pamatto, ma kandi 'dukkhamidan'ti dayhamano.
Meditate, bhikkhu! Do not be heedless. Do not let your mind whirl in the strands of sense-pleasure. Do not, heedless, swallow the iron ball — and then cry out, 'This is suffering!' as you burn.
— Dhammapada 25.12
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.