What is the meaning of "Atarta Shenas Tovasecha"?
Rashi: Via rain, You crown with all good the year that You want to benefit.
Radak: A year of satiation, which is a year of Your good, You crown it with every good thing. This is like "ka'Tzinah Ratzon Taterenah" (5:13).
Malbim: This refers to "Yisro'a'u Af Yashiru" (verse 14) - then they will sing "Atarta Shenas Tovasecha", i.e. You clothed the year with a crown of beauty.
What are "Magalecha"?
Rashi: It is Shamayim, which is dust of Your feet.
Radak: They are clouds, just like they are called Susei Kel - "Darachta va'Yam Susecha", "Markevosecha Yeshu'ah" (Chabakuk 3:15, 8).
Malbim: It is a circular path. When rain falls in Midbaros, where flocks graze, it goes in a circular path that turns away from the straight path of settled places.
What is the meaning of "Yir'afun Dashen"?
Rashi: It drips fat.
Radak: [The clouds] drip rain, from which will be fatness [of the land].