What is the meaning of "Hemah Yovedu"?
Radak #1: Some researchers say that the world has a deadline, after which it will return to "Sohu va'Vohu" (Bereishis 1:2) and void, like it was.
Radak #2: Some say that it has no end, even though it had a beginning. The verse means that [Shamayim and Eretz] will perish if You want, and You will always exist.
Radak #3: The individuals [in Shamayim va'Aretz] will perish, but the Klal (Shamayim va'Aretz themselves) will last forever.
Malbim: Everything that has a beginning, it has an end. Only You persist without change.
Why does it say "ka'Beged Yivlu"?
Malbim: The Hiyuli (substance from which everything was created) constantly removes its form and 'wears' a different form. There are two comparisons to a garment. (a) A garment withers by itself if left for a long time. Every composition comes apart. Also refer to 102:27:3:3.
What is the significance of "ka'Levush Tachalifem"?
Rashi: This is like a person who turns his garment inside out, to remove it.
Radak: This is like a person who removes this garment and wears another. So You will change [Shamayim va'Aretz] or replace them with others, if You desire. No one can protect against You!
Malbim: The Hiyuli constantly removes its form and 'wears' a different form, like one who wears garments and always switches to wear different garments.
