Why are all his days painful?
Ibn Ezra: As long as he is awake, he is pained and angry that things do not happen like he intended.
Rashbam: He thinks and pursues [how] to acquire money.
Seforno: Efforts to acquire matters that perish, they also cause pain, which distracts him from contemplation and striving to acquire eternal perfection.
Metzudas David: It is due to mishaps.
What causes anger?
Metzudas David: The affairs that he is forced to engage in them, for usually it is unlike his desire.
What is "Inyano"?
Rashi: It is his norm.
Why does it say "Gam ba'Laylah Lo Shachav Libo"?
Rav Sadya Gaon: Even at night his heart does not rest. Rashbam - even when he lies down, his heart does not lie (rest). He always thinks how [to ensure that] his money will not leave his hand - "veha'Sava Einenu Mani'ach Lo Lishon" (5:11).
Ibn Ezra: Also at night his heart does not cease from dreams. Most dreams are based on his thoughts during the day.
Metzudas David: He is distracted with thoughts of gathering acquisitions.
Why does it say "Gam Zeh Hevel Hu"?
Metzudas David: The mere distraction of thoughts, even without the toil to gather, is Hevel.
