Isaiah 19:20

And it, the altar or pillar last mentioned, shall be for a sign and for a witness unto the Lord, to testify that they own the Lord for their God. They shall cry unto the Lord because of the oppressors; being sorely distressed, and finding the weakness of their idols, they shall turn unto the true God. A Saviour, and a great one; a great or mighty Saviour, by a common figure called hendiaduo, as a cloud and smoke is put for a smoking cloud, Isaiah 4:5; or, a Saviour and a Prince, even Christ, who is so called, Acts 5:31, as is evident from the whole context, which apparently speaks of gospel times. And the emphatical phrase here used directed them to look for an extraordinary Saviour.