Among many great shlokas of Manusmiriti, “Satyam Bruyat Priyam Bruyat” सत्यं ब्रूयात् प्रियं ब्रूयात् is a great piece of wisdom and virtue.
“Satyam bruyat – priyam bruyat- na bruyat satyam apriyampriyam cha nanrutam bruyat – esha dharmah sanatanah”
Speak the Truth, speak pleasantly,Do not speak the Truth in an unpleasant mannerEven if pleasant, do not speak untruth,
“He shall say what is true, and he shall say what is agreeable; he shall not say what is true, but disagreeable; nor shall he say what is agreeable, but untrue; this is the eternal law.”
In Bhagavad Gita, Lord Krishna says about the sombreness of speech. He preaches the followers to use words that are satyam (truthful), priyam (pleasant), and hitam(beneficial).