Dhammapada · 10.13

Na naggacariyā na jaṭā na paṅkā, nānāsakā thaṇḍilasāyikā vā;Rajojallaṃ ukkuṭikappadhānaṃ, sodhenti maccaṃ avitiṇṇakaṅkhaṃ.

Na naggacariya na jata na panka, nanasaka thandilasayika va; Rajojallam ukkutikappadhanam, sodhenti maccam avitinnakankham.

Not going naked, nor matted hair, nor smearing mud, nor fasting, nor sleeping on the ground, nor dust-and-dirt, nor squatting exertion — these do not purify a mortal who has not crossed doubt.

— Dhammapada 10.13

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.