Dhammapada · 23.4
Na hi etehi yānehi, gaccheyya agataṃ disaṃ;Yathāttanā sudantena, danto dantena gacchati.
Na hi etehi yanehi, gaccheyya agatam disam; Yathattana sudantena, danto dantena gacchati.
Not by these vehicles could one go to the untrodden region. But the well-tamed one, by his tamed self, reaches there.
— Dhammapada 23.4
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.