Exodus 10:1-2

THE LORD said to Moses, Go to Pharaoh, for I have made his heart hard, and his servants' hearts, that I might show these My signs [of divine power] before him, And that you may recount in the ears of your son and of your grandson what I have done in derision of the Egyptians and what things I have [repeatedly] done there–My signs [of divine power] done among them–that you may recognize and know that I am the Lord.