Dhammapada · 17.12

Vacīpakopaṃ rakkheyya, vācāya saṃvuto siyā;Vacīduccaritaṃ hitvā, vācāya sucaritaṃ care.

Vacipakopam rakkheyya, vacaya samvuto siya; Vaciduccaritam hitva, vacaya sucaritam care.

Guard against angry speech, be restrained in speech. Abandoning verbal misconduct, practice verbal good conduct.

— Dhammapada 17.12

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.