Shankaracharya's commentary, trans. Alladi Mahadeva Sastry (1897)
[1]The speech which causes no excitement and is true, as also pleasant and beneficial, and also the practice of sacred recitation, are said to form the austerity of speech.
BG 17.15
अनुद्वेगकरं वाक्यं सत्यं प्रियहितं च यत् । स्वाध्यायाभ्यसनं चैव वाङ्मयं तप उच्यते ॥
anudvega-karaṃ vākyaṃ satyaṃ priya-hitaṃ ca yat | svādhyāyābhyasanaṃ caiva vāṅ-mayaṃ tapa ucyate ||
"Speech tapas: non-disturbing, true, agreeable, beneficial words — plus daily svādhyāya (sacred study)."
All public-domain translations
4 translations · all pre-1928 or released to public domain · sources
Swami Swarupananda, Srimad Bhagavad Gita (1909)
[4]Speech which causes no vexation, and is true, as also agreeable and beneficial, and regular study of the Vedas — these are said to form the austerity of speech.
K.T. Telang, Sacred Books of the East Vol. 8 (1882)
[9]The recitation of texts, and speech which causes no annoyance, (which is) true, agreeable, and beneficial — are said to be the penance of speech.
K.M. Ganguli, The Mahabharata, Bhishma Parva (1883–96)
[13]The speech which causes no agitation, which is true, which is agreeable and beneficial to study of one's own scripture, are said to be the penance of speech.