Who are "Mesayich"?
Rashi: Your Giborim, who die in your wars; they go out in the army, counted.
Radak: This curse is for the men. It addresses Tziyon mentioned above ("Benos Tziyon" - 16).
Malbim: The weak men of Tziyon. The enemy will kill them in their houses (they did not go to fight).
What does it say about "Gevurasech"?
Radak: They will die in war. "Mesayich" applies to also to "Gevurasech". These are the strong men on which Tziyon relied. This is like Targum Yonasan, Avdei Nitzchanech (those who make you victorious).
Malbim: The strong will not die like valiant men who risk their lives in battle - even if they die, their Gevurah is remembered. Rather, they will fall like weak cowards. Gevurasech, i.e. valiance itself, will fall; it will be seen that you have no Gevurah in war.
