It will be a sign and witness to the Lord Almighty in the land of Egypt. When they cry out to the Lord because of their oppressors, he will send them a savior and defender, and he will rescue them. (v. 20)

I believe that this prophecy speaks to all oppressed people, "When they cry out to the Lord because of their oppressors, he will send them a savior and defender, and he will rescue them." Have we cried out to the Lord because of our oppressors? Yesm we have but we must remember the words of Jesus in  Matthew 7:7,  "Ask and keep on asking and it will be given to you; seek and keep on seeking and you will find; knock and keep on knocking and the door will be opened to you." 

Please read Isaiah 18-20.

May the Lord richly bless you!