Who are "Kol Am ha'Aretz"?
What reputation will they get?
Rashi: All nations will praise them ? there is no nation merciful like this, that buries its enemies who tried to kill it! Radak ? even though Yisrael buried them only to purify the land [and not for the sake of the dead, they will get a good reputation].
Malbim: Normally, a nation would not bury people who died in a plague, and especially if they died many days ago. Then, they increase decay and plague, and these cling to those who bury them. They separate people special [to bury them], and the nation bewares of [contact with] those who bury, lest the plague cling to them. However, all Am ha'Aretz will bury Magog. All will see that Hashem guards them, and they do not fear plague ? "Lo Sira mi'Pachad Laylah mi'Dever ba'Ofel Yahaloch" (Tehilim 91:5). 1
Even though they will kill each other, Malbim (6) expounded that there will also be a plague.
Why is it called "Yom Hikavdi"?
Malbim: Hashem's honor and Hashgachah Pratis on Yisrael will be seen, and how He guards them from every mishap ? "Hashem Yishmarcha mi'Kol Ra" (Tehilim 121:7).