Solomon
Proverbs 14:5ESV·traditional attribution

A faithful witness does not lie, but a false witness breathes out lies.

Matthew Henry Presbyterian @wholebiblehenry

In the administration of justice much depends upon the witnesses, and therefore it is necessary to the common good that witnesses be principled as they ought to be; for, 1. A witness that is conscientious will not dare to give in a testimony that is in the least untrue, nor, for good-will or ill-will, represent a thing otherwise than according to the best of his...

John Gill Reformed Baptist @doctorgill

A faithful witness will not lie,.... For that would be contrary to his character as faithful; and as he will not witness to a falsehood upon oath in a court of judicature, so neither will he tell a lie in common conversation.

Jamieson-Fausset-Brown Reformed @jfbcommentary

A faithful witness, &c.--one tested to be such. utter lies--or, "breathe out lies"--that is, habitually lies (Pro 6:19; compare Act 9:1). Or the sense is, that habitual truthfulness, or lying, will be evinced in witness-bearing.