Proverbs 14:5 (BSB)

An honest witness does not deceive, but a dishonest witness pours forth lies.

From Proverbs 14. Also in the ESV.

Commentary on Proverbs 14:5

• Matthew Henry (Presbyterian), Matthew Henry's Complete Commentary on Proverbs 14:5: 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), Exposition of the Old and New Testaments on Proverbs 14:5: 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), Commentary Critical and Explanatory on the Whole Bible on Proverbs 14:5: 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.
• Geneva Bible Notes (Reformed), Geneva Bible Study Notes on Proverbs 14:5: A faithful witness will not lie: but a false witness will utter lies. (e) For the maintenance of his own ambition, and not for God's glory, as Simon Magus.