Contradiction with Exodus 20:13
"Thou shalt not kill." Numbers 31:48 accounts for military actions and killing, which contrasts with the commandment against killing.
Exodus 20:13: Thou shalt not kill.
Contradiction with Matthew 5:44
"But I say unto you, Love your enemies." Numbers 31:48 involves actions of war, opposing the teaching to love one's 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 Romans 12:19
"Dearly beloved, avenge not yourselves, but rather give place unto wrath." This contrasts with the actions of vengeance in Numbers 31:48.
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 Matthew 26:52
"Put up again thy sword into his place: for all they that take the sword shall perish with the sword." Numbers 31:48 involves bearing arms, contrary to the teaching against it.
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?
Contradiction with Proverbs 25:21
"If thine enemy be hungry, give him bread to eat." Numbers 31:48 details military conflict instead of providing for enemies.
Proverbs 25:21: If thine enemy be hungry, give him bread to eat; and if he be thirsty, give him water to drink: