The Precept Against False Speech

"The Precept Against False Speech"
From Nagarjuna's Treatise on the Great Perfection of Wisdom
(Dharmamitra Translation)

As for false speech, if there is a thought which is not pure, if one wishes to deceive another, if one hides the truth, and if one speaks forth words which differ from the truth, one generates the karma of the mouth. This constitutes "false speech." The offense of false speech arises from the sound of the words and mutual understanding. If there is no understanding, then although they are untrue words, there is no offense of false speech. As for this false speech, if one does know yet says that one does not know, if one does not know yet says that one does know, if one has seen yet says that one has not seen, has not seen yet says that one has seen, has heard yet says that one has not heard, or has not heard yet says that one has heard, this constitutes false speech. If one has not done this then this qualifies as not committing false speech.