Contradiction with Matthew 5:39
In 1 Samuel 20:40, weapons are part of a context that involves protection and potential conflict, whereas Matthew 5:39 advocates for non-violence and turning the other cheek.
Matthew 5:39: But I say unto you, That ye resist not evil: but whosoever shall smite thee on thy right cheek, turn to him the other also.
Contradiction with Romans 12:19
1 Samuel 20:40 involves handling weapons which implies self-defense or conflict, while Romans 12:19 advises against taking vengeance and leaving it to God.
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
1 Samuel 20:40 is set in a context where weapons might be needed, but Exodus 14:14 emphasizes that the Lord will fight for you, and you should hold your peace.
Exodus 14:14: The LORD shall fight for you, and ye shall hold your peace.
Contradiction with Matthew 26:52
The presence of weapons in 1 Samuel 20:40 is contrasted with Matthew 26:52, which states that all who take up the sword will perish by the sword.
Matthew 26:52: Thinkest thou that I cannot now pray to my Father, and he shall presently give me more than twelve legions of angels?