Exodus 23:4
"If thou meet thine enemy’s ox or his ass going astray, thou shalt surely bring it back to him again."
Cross References (ranked by relevance)
1 Thessalonians 5:15
See that none render evil for evil unto any man; but ever follow that which is good, both among yourselves, and to all men.
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;
Proverbs 25:21
If thine enemy be hungry, give him bread to eat; and if he be thirsty, give him water to drink: