1)
Why does it say "Tetzei Rucho"?
1.
Radak: How can man save others? He cannot save even himself; he does not rule over his Ru'ach! It can leave suddenly, and he will return to his land (be buried)!
2.
Malbim: Trust must be in something permanent, and not in something that ceases. Man's Ru'ach leaves him, and the body returns to his land - "va'Yashov he'Afar Al ha'Aretz keshe'Hayah veha'Ru'ach Tashuv" (Koheles 12:7).
2)
What are "Eshtonosav"?
1.
Rashi: His intents. Radak - also in Arame'ic, "u'Malka Ashis" means Choshev (thinks).
