Why do they say "Shav Avod Elokim"?
Rashi: We served him for naught, for we will not receive reward.
Malbim: You say that even though Hashem answered for serenity of Resha'im, afflictions of Tzadikim are still difficult. They did not sin, and they live a life of pain! Therefore you say that Avodas Hashem has no benefit for the One who is served, and the one who serves. He does not need our Avodah - "Im Tzadakta Mah Titen Lo" (Iyov 35:7). There is no benefit for the one who serves - refer to 3:14:2:1.
What do we learn from "u'Mah Betza Ki Shamarnu Mishmarto"?
Malbim: We did not gain anything from serving Him. There was no reward, only the opposite! Refer to 3:15:1:2.
What is the meaning of "Kedoranis"?
Rashi: With a lowly spirit.
