He that speaketh that which he knoweth, sheweth forth justice: but he that lieth, is a deceitful witness.

that

Proverbs 14:5,25 A faithful witness will not lie: but a deceitful witness uttereth a lie. . . .

1 Samuel 22:14,15 And Achimelech answering the king, said: And who amongst all thy servants is so faithful as David, who is the king's son in law, and goeth forth at thy bidding, and is honourable in thy house? . . .

but

Proverbs 6:19 My son, keep the commandments of thy father, and forsake not the law of thy mother.

Proverbs 19:5,28 A false witness shall not be unpunished: and he that speaketh lies, shall not escape. . . .

Proverbs 21:28 A lying witness shall perish: an obedient man shall speak of victory.

Proverbs 24:28 Be not witness without cause against thy neighbour: and deceive not any man with thy lips.

Matthew 15:19 For from the heart come forth evil thoughts, murders, adulteries, fornications, thefts, false testimonies, blasphemies.

Matthew 26:59 And the chief priests and the whole council sought false witness against Jesus, that they might put him to death.

Acts 6:13 And they set up false witnesses, who said: This man ceaseth not to speak words against the holy place and the law.

1 Peter 3:16 But with modesty and fear, having a good conscience: that whereas they speak evil of you, they may be ashamed who falsely accuse your good conversation in Christ.