What is the significance of "Ken Tzedakah l'Chayim"?
Rashi: The Emes of Tzedakah, its end is for life. "Ken" is Emes (R. Yonah - without any doubt), like "Ken Bnos Tzlafchad Dovros" (Bamidbar 27:7).
Malbim: Seeding Tzedakah with song, he will reap true wages, for the acts of Tzedakah are trustworthy, to bring to life. It brings life in this world ("u'Tzdakah Tatzil mi'Maves" - 10:2) and real life in the world to come.
How is pursuing evil for his own death?
Malbim: Pursuit is striving to get something quickly. In nature, evil is far from the Rasha; he chases to bring it before its time. This leads to death. (a) Through his evil, bad will come to his body, and he will die before his time. (b) His Nefesh will die in the world to come - "Pe'ulas Tzadik l'Chayim Tevu'as Rasha l'Chatas" (10:16).
What is the connection of the two halves of the verse?
R. Yonah: Just like Tzedakah is for life, without any doubt, so pursuing evil - constantly seeking to harm people - is for his own death, without any doubt.
