The words that does not disturb any body and which is agreeable, true and beneficial, and the diligent study of the Vedas, is the penance of speech.
अनुद्वेगकरं वाक्यं सत्यं प्रियहितं च यत्। स्वाध्यायाभ्यसनं चैव वारड्मयं तप उच्यते॥