If I'm not mistaken this these two passages are the only ones where enemies are fed in the Bible:

Romans 12:20 (KJV) 20 Therefore if thine enemy hunger, feed him; if he thirst, give him drink: for in so doing thou shalt heap coals of fire on his head.

12th book:
2 Kings 6:21 (KJV) 21 And the king of Israel said unto Elisha, when he saw them, My father, shall I smite [them]? shall I smite [them]?

2 Kings 6:22 (KJV) 22 And he answered, Thou shalt not smite [them]: wouldest thou smite those whom thou hast taken captive with thy sword and with thy bow? set bread and water before them, that they may eat and drink, and go to their master.

2 Kings 6:23 (KJV) 23 And he prepared great provision for them: and when they had eaten and drunk, he sent them away, and they went to their master. So the bands of Syria came no more into the land of Israel.