What is "Somu"?
Rashi: It is an expression of astonishment, Hishtomemu 1 . It is a command, like "Im Ko Yomru Eleinu Domu" (Shmuel I, 14:9).
Radak: It is an expression of Shemamah (desolation). The world is proper to be desolate due to this sin.
Radak citing Targum Yonasan: [Shamayim] should mourn [over the land of Yisrael that will be desolate].
Malbim: The astonishment is at the evils that Yisrael did.
What is "Sa'aru"?
Rashi: It is an expression of Sa'ar (agitation).
Radak: It is an expression of Sa'arah (storm).
Malbim: Be upset and pained [at the Churban of Yisrael].
Why did He say "Charvu Me'od"?
Rashi: As if you are destroyed, due to the Beis ha'Mikdash, which will be destroyed.
Radak: This is a command. There is Kamatz Chataf under the Ches.
Radak: The Mesores says that there is no Chataf (it is a regular Kamatz). R. Yonah says that some explain it like "Charvu Pnei ha'Adamah" (Bereishis 8:13). It is a command, but there is a Dagesh, like "Parku Nizmei ha'Zahav" (Shemos 32:2). R. Yonah disagreed due to the Mesorah.
