To whom should Hashem return Tzedakah?
Rashi: To every Tzadik [Radak - like I did].
How should Hashem return the Tzedakah?
Malbim: The person should have an opportunity to do the Tzedakah again, just like here David was righteous and did not kill Sha'ul [when he could have, in the cave], and now the opportunity came a second time.
What is the meaning of "Nesancha? b'Yad"?
Radak, based on Targum Yonasan: It is as if says Nesancha? b'Yadi. Also "Azi v'Zimras Kah" (Shemos 15:2) is as if says v'Zimrasi.
Radak: Perhaps it is Samuch, even though the noun after it is omitted and there is a Kamatz under the Yud 1 . It is as if says 'in the hand of one of my men.'
If it were Samuch, there would be a Patach under the Yud. (PF)