1)
Why does it discuss a "Nadiv"?
1.
Radak: This includes a Shu'a. He is the opposite of a Kilai, who counsels foul words. The Nadiv counsels generosity!
2.
Malbim (7-8): The verses show why a Kilai cannot be called Nadiv, for he is the opposite. His heart and mind are full of generosity, to pardon what is his.
2)
What is the meaning of "Al Nedivos Yakum"?
1.
Rashi: Due to his generosity, he will be revived.
2.
Malbim: The researcher said that a Nadiv is one whose generosity is not for another purpose based on self-love. E.g. it is a means to get renown, glory
