Contradiction with Proverbs 25:21
1 Samuel 25:4 involves David asking for provisions, while Proverbs 25:21 teaches to provide for enemies without expectation.
Proverbs 25:21: If thine enemy be hungry, give him bread to eat; and if he be thirsty, give him water to drink:
Contradiction with Matthew 5:44
In 1 Samuel 25:4, David seeks benefit from Nabal, whereas Matthew 5:44 instructs to love and expect nothing from enemies.
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 Luke 6:30
David's approach suggests a request, yet Luke 6:30 advises to give without expecting to receive back.
Luke 6:30: Give to every man that asketh of thee; and of him that taketh away thy goods ask [them] not again.