sn The expression “I will do to Pharaoh” always refers to the plagues. God would first show his sovereignty over Pharaoh before defeating him.
tn The expression “with a strong hand” (וּבְיָד חֲזָקָה, uvéyad khazaqah) could refer (1) to God’s powerful intervention (“compelled by my strong hand”) or (2) to Pharaoh’s forceful pursuit (“he will forcefully drive them out”). In Exod 3:20 God has summarized what his hand would do in Egypt, and that is probably what is intended here, as he promises that Moses will see what God will do. All Egypt ultimately desired that Israel be released (12:33), and when they were released Pharaoh pursued them to the sea, and so in a sense drove them out—whether that was his intention or not. But ultimately it was God’s power that was the real force behind it all. U. Cassuto (Exodus, 74) considers that it is unlikely that the phrase would be used in the same verse twice with the same meaning. So he thinks that the first “strong hand” is God’s, and the second “strong hand” is Pharaoh’s. It is true that if Pharaoh acted forcefully in any way that contributed to Israel leaving Egypt it was because God was acting forcefully in his life. So in an understated way, God is saying that when forced by God’s strong hand, Pharaoh will indeed release God’s people.”