Contradiction with Exodus 23:7
This verse advises to keep oneself far from a false matter, which implies avoiding falsehood, contradicting the fate of false witness in Proverbs 19:9.
Exodus 23:7: Keep thee far from a false matter; and the innocent and righteous slay thou not: for I will not justify the wicked.
Contradiction with Proverbs 12:22
States that lying lips are an abomination to the Lord, while Proverbs 19:9 specifies a consequence, which might seem conflicting as the verses alone have different emphases.
Proverbs 12:22: Lying lips [are] abomination to the LORD: but they that deal truly [are] his delight.
Contradiction with 1 John 1:9
If we confess our sins, God is faithful to forgive us, which can be seen as contradicting the consequence of punishment for false witness in Proverbs 19:9.
1 John 1:9: If we confess our sins, he is faithful and just to forgive us [our] sins, and to cleanse us from all unrighteousness.
Contradiction with Proverbs 14:5
A faithful witness will not lie, yet it focuses on the behavior of truthful witnesses, not the fate of false ones as emphasized in Proverbs 19:9.
Proverbs 14:5: A faithful witness will not lie: but a false witness will utter lies.
Contradiction with Hebrews 8:12
Assures that God will forgive iniquities and remember sins no more, which might be considered contradictory to the punitive measure in Proverbs 19:9.
Hebrews 8:12: For I will be merciful to their unrighteousness, and their sins and their iniquities will I remember no more.