And it shall come to pass— The prophet intends here to denote the extreme desertion of the land, and in consequence the great growth of the grass and food, which there shall not be sufficient cattle to eat. Certainly, therefore, the few men remaining might themselves eat the fat of the land, when there were scarcely any to share with them, and none to purchase of them. The subsequent verses set forth in strong terms the desolation of the land.
Related Commentaries of Isaiah 7:21
Isaiah 7:21-22
21 And it shall come to pass in that day, that a man shall nourish a young cow, and two sheep;
22 And it shall come to pass, for the abundance of milk that they shall give he shall eat butter: for butter and honey shall every one eat that is left in the land.f