And the Lord shall smite Egypt - That is, in the manner described in the previous part of this prophecy Isaiah 19:2-10.
And heal it - Or restore it to more than its former splendor and prosperity, as described in the previous verses Isaiah 19:18-20. He shall send it a saviour; he shall open new sources of prosperity; and he shall cause the true religion to flourish there. These advantages would be more than a compensation for all the calamities that he would bring upon it.
And they shall return - These calamities shall be the means of their conversion to Yahweh.