1)
Why will their food be Tamei?
1.
Rashi: It will be repulsive. 1
2.
Radak: In Galus they cannot guard their food from Tum'ah, and they cannot eat in cleanliness.
3.
Malbim: It will be Tamei with the Tum'ah of Goyim.
1
Rashi (Sotah 4b): So the Gemara expounds that "Tamei" is despised, and 'equates' eating bread with wet hands to eating Tamei bread. Ritva (Chulin 107a) - no. Rather, the water becomes Tamei, and it is Metamei the bread.
