Charles Ellicott Commentary Isaiah 19:20

"And it shall be for a sign and for a witness unto Jehovah of hosts in the land of Egypt; for they shall cry unto Jehovah because of oppressors, and he will send them a saviour, and a defender, and he will deliver them." — Isaiah 19:20 (ASV)

For they shall cry unto the Lord because of the oppressors ... —The words are almost an anticipation of the great truth proclaimed in John 4:21. The prayers of the worshippers in spirit and in truth, whether Jews or proselytes, in Egypt would find as immediate an access to the ear of Jehovah as if they had been offered in the Temple at Jerusalem.

If the people suffered under the oppression of a Pharaoh, or a Cambyses, or a Ptolemy, and prayed for deliverance, He would as certainly send them a saviour who would free them from the yoke as He had sent saviours to Israel in the past in the persons of the judges (Judges 3:9; Judges 3:15; Judges 4:4). It is open to us to see a still higher fulfilment in the fact that the message of the Gospel brought peace and joy to those who were weary and heavy laden in Egypt, as well as in Galilee; to those who were looking for redemption in Alexandria no less than to those who were looking for it in Jerusalem.