Bhagavad Gita 17.15

अनुद्वेगकरं वाक्यं सत्यं प्रियहितं च यत्।स्वाध्यायाभ्यसनं चैव वाङ्मयं तप उच्यते॥

anudvegakaraṃ vākyaṃ satyaṃ priyahitaṃ ca yat |svādhyāyābhyasanaṃ caiva vāṅmayaṃ tapa ucyate ||

Speech that causes no excitement, is truthful, pleasant, and beneficial; the practice of studying the Vedas is called austerity of speech.

Speech that hurts no one, that is true, pleasant to listen to, and beneficial, and the constant study of the scriptures—this is austerity of speech.

Our plain-language meaning of this verse is waiting for scholar review.