The Egyptians shall know that I am the Lord— The great design of this wonderful exhibition of miracles, was to prove to the Egyptians, and so to all the world, that the Jehovah of the Jews, the Almighty Deliverer of his people Israel, was not only superior to theirs, and to all the gods of the nations; but also, that he was the Sovereign Ruler and Controuler, as well as the Maker, of all created things: and if we consider the miracles in this view, we shall find that they all tend to demonstrate the uncontroulable sovereignty of Jehovah over all nature. See ch. Exodus 10:2 Exodus 14:4; Exodus 14:18, &c.
Related Commentaries of Exodus 7:5
Exodus 7:5
5 And the Egyptians shall know that I am the LORD, when I stretch forth mine hand upon Egypt, and bring out the children of Israel from among them.