Why does it mention doing Tzedakos?
Radak: After saying that Hashem heals him from his illness and does Tzedakah with him, it says that so is His way - He does Tzedakah with His creations.
Malbim: According to letter of the law, a sinner should die. Hashem does not act according to Mishpat, rather, based on supreme Chesed. He does not look at man's act and Midas ha'Din.
Why does it say "u'Mishpatim l'Chol Ashukim"?
Radak: Also regarding Bein Adam l'Chavero, He saves the oppressed from the oppressor. The prefix Lamed in "l'Chol" means for the sake of; he does Mishpat to the oppressors for the sake of the oppressed. This is like "Imri Li Achi Hu" (Bereishis 20:13). "L'Chol" teaches, no matter which nation the oppressed 1 is from.
Malbim: Mishpatim are only for the oppressed, for sins Bein Adam l'Chavero. This He does based on Midas ha'Din. Teshuvah does not help until he returns the theft.
Many texts of Radak say 'the oppressor'; it seems that this is a mistake. (PF)
