What is the meaning of "Hikon v'Hachen Lecha"?
Rashi: Summons yourself, and prepare for yourself other armies.
Radak: Summons yourself, and prepare for yourself your entire congregation.
Why does it add "ha'Nikhalim Alecha"?
Malbim: Among this army will be people who gather against you (like "va'Yakhel Aleihem Korach Es Kol ha'Edah" - Bamidbar 16:19). The Yishmaelim, i.e. Paras, Kush and Put, are primarily against Gog.
How will you be for them Mishmar?
Rashi: Kings pay attention to how their soldiers go out, and they appoint watches, lest destroyers come against the army at night.
Radak: They will guard which way you go, and go with you.
Malbim: Guard them from doing evil. When the Yishmaelim will begin to do evil in Yerushalayim, the Edomim will stand against them and kill them. This will cause Yishmaelim to kill Edomim; man's sword will be against his brother, like I explained above (refer to 32:17:3:1).
