What is the meaning of "b'Chol ha'Aretz Yatza Kavam"?
Rashi: The line on which Shamayim is spread, extends over the entire land.
Radak: The structure of the spheres and stars extends in the entire land. "Kavam" are buildings. The same applies to "Kav l'Kav" (Yeshayah 28:10), for the building is made via extending a line.
Malbim: This telling [of Hashem's honor] is not limited to a particular place. Their Kav goes to the entire land, also to unsettled parts. Hashem stretched the Kav on the general building [of the world], and it hangs on Belimah (void).
What is the meaning of "uvi'Ktze Sevel Mileihem"?
Malbim: Sevel is the settled part of the world; this is where their words are, for there the creations tell Hashem's Chachmah.
What is the meaning of "la'Shemesh Sam Ohel Bahem"?
Rashi (from Tanchuma Tetzaveh 6): (Hashem made a tent for the sun in Shamayim.) This shows that it has a container.
Radak: Hashem made a place for the sun on [one of] the spheres. The verse discusses the sun [and not other celestial bodies], because it is the great luminary, and people, other living beings and vegetation benefit from it more than from the others, from its light and heat. Bahem refers to one of [the spheres], like "va'Yikaver b'Arei Gil'ad" (Shoftim 12:7). There is one sphere for each of the seven Kochvei Leket (the sun, moon and five closest planets); the sun is on the fourth. "Va'Yiten Osam Elokim bi'Rki'a ha'Shamayim" (Bereishis 1:17), and not Al ha'Raki'a. Also a Midrash (Tanchuma) says that the stars are fixed in the Raki'a like nails fixed in a door.