Why does it mention Edom?
Radak: All those mentioned did evil to Yisrael, and all of them fell to the sword.
Malbim: Afterwards, Edom and its kings will come. They will fight valiantly. It seems that the last three will combat the first three ? Egypt against Meshech and Tuval, Ashur against Edom, and Eilam against Nesichei Tzafon (30). Chazal said 1 that Gog will fight three wars; they learned from here.
I found so in Batei Midrashos, Alpha Beisa, DH v'Achar. (PF)
What do we learn from "Es Arelim Yishkavu"?
Malbim: They will be buried with Arelim, but not with Yishmaelim, who are circumcised. Regarding Ashur, it does not say that they will be buried among Arelim. The Arelim of Edom (Ashur's opponent) and its kings will be buried by themselves.
