पापेनैव नृणाम् वाणी भवेत कटुक भाषिणीम्
दैन्य मात्सर्य परमा शुभाशुभ विवर्जिता
The पाप (deep seated (unconscious, subconscious and conscious) prejudices, envy, jealousy, contempt, hatred, arrogance, fanaticism, dogmatism, selfishness, lust, frustration, depression, fear, anxiety, guilt complex, inferiority complex etc.) vitiate our communication and make it scalding; with no concern for the benevolent or disastrous effect on the other/s.

INDIAN SANSKRIT LITERATURE
Exact source is not known.