Contradiction with Matthew 5:44
Psalms 35:23 asks for judgment against enemies, whereas Matthew 5:44 instructs to love your enemies and pray for those who persecute you.
Matthew 5:44: But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you;
Contradiction with Romans 12:19
Psalms 35:23 calls for God to awake to judgment, but Romans 12:19 teaches to not avenge ourselves and leave room for God's wrath.
Romans 12:19: Dearly beloved, avenge not yourselves, but [rather] give place unto wrath: for it is written, Vengeance [is] mine; I will repay, saith the Lord.
Contradiction with Exodus 14:14
Psalms 35:23 seeks active intervention, while Exodus 14:14 advises to hold peace and let the Lord fight for you.
Exodus 14:14: The LORD shall fight for you, and ye shall hold your peace.
Contradiction with Proverbs 24:17
Psalms 35:23 implies rejoicing in anticipated judgment, whereas Proverbs 24:17 warns against rejoicing when your enemy falls.
Proverbs 24:17: Rejoice not when thine enemy falleth, and let not thine heart be glad when he stumbleth:
Contradiction with Luke 6:28
Psalms 35:23 asks for defense against persecution, in contrast to Luke 6:28, which encourages blessing those who curse you.
Luke 6:28: Bless them that curse you, and pray for them which despitefully use you.
Contradiction with 1 Peter 3:9
Psalms 35:23 petitions for judgment, unlike 1 Peter 3:9, which advises not to repay evil for evil.
1 Peter 3:9: Not rendering evil for evil, or railing for railing: but contrariwise blessing; knowing that ye are thereunto called, that ye should inherit a blessing.