1)
What is the meaning of "Yode'a Hashem Yemei Semimim"?
1.
Rashi: He recognizes the deeds of their days.
2.
Radak: He supervises over them to lengthen their days.
3.
Malbim: This is another difference between one who trusts and evildoers. The latter do not live half their [allotted] days, but Hashem knows the days of Temimim, and guards that their days be complete.
2)
What is "Nachalasam"?
1.
Rashi: It is the reward that they will get [Radak - in the world to come].
2.
Malbim: [The Rasha will not bequeath his wealth to his sons,] but the Tzadik's inheritance will be l'Olam (forever to his descendants).