Philo Judaeus De Mutatione Nominum 240

[240] Therefore the most excellent, and most perfect kind of purification is this, not to admit into one’s mind any improper notions, but to regulate it in peace and obedience to law, the ruler of which principles is justice. The next kind is, not to offend in one’s language either by speaking falsely, or by swearing falsely, or by deceiving, or by practising sophistry, or by laying false informations; or, in short, by letting loose one’s mouth and tongue to the injury of any one, as it is better to put a bridle and an insuperable chain on those members.