1)
What is the meaning of "Sibarti"?
1.
Rashi: I hoped.
2)
For what salvation did he hope?
1.
Radak: Salvation of the Nefesh.
3)
What do we learn from "u'Mitzvosecha Asisi"?
1.
Radak: I did not do Mitzvos amidst hope for reward, rather, like Your command upon me.
2.
Malbim: Even though a Mitzvah does not save from the Yetzer ha'Ra (it only protects from evil - Sotah 21a), I hoped for Your salvation also in the merit of the Mitzvah - one's Yetzer ha'Ra overpowers him every day. If Hashem would not help him, he could not overcome it (Kidushin 30b).