1)
What is the significance of "scooping coals on his head"?
1.
Rashi: [What you give to him to eat and drink] is like drawing coals from a fire to put on his head 1 . Drawing coals from a fire is called Choseh - "Lachtos Esh mi'Yakod" (Yeshayah 30:14).
1
Malbim: He feels so, for he remembers that he sinned against you and did evil to you, and he will be ashamed that now he must receive food and water from you, in place of his evil.
2)
What will Hashem pay to you?
1.
Rashi: He will make him have Shalom with you; he will not overpower you.
2.
Malbim: You will receive reward for the Tzedakah that you did. If you take vengeance and do not give to him, you will not receive reward.
