It is stated in Shemos Parshas Beshalach 14:4 the following: "And I will harden Pharaoh's heart, and he will pursue them, and I will be glorified through Pharaoh and through his entire army, and the Egyptians will know that I am Hashem. And they did so." Ok this is fine, but then later on in the perek it says in (14:17): "And I, behold! I shall harden the hearts of the Egyptians, and they will come after you, and I will be glorified through Pharaoh, and through all his army, through his chariots, and through his horsemen". Why is all of this repeated about how Hashem will be glorified through his nation and mitzrayim etc.and also why does it need to change Pharaoh to the Egyptians in the 2 Posukim? Pharaoh is a king leader of the whole nation why does it need to harden both of their hearts surely if Pharaoh's heart is hardened then the Egyptians hearts will be hardened also?
See both Ibn Ezra and Seforno's explanations on 14:18. The term "Egyptians" in verse 18 means "the rest of them". Essentially, the two commentaries state that the Egyptians will realize that Pharoah's heart was hardened against God, and they will repent so that they wouldn't drown in the sea. But, it was God's will that Pharoah alone die in the sea.
I have trouble resolving this explanation with the literal words in verse 17 that states that God will harden the hearts of the Egyptians. Comments / assistance appreciated.
surely if Pharaoh's heart is hardened then the Egyptians hearts will be hardened also?
Actually, this is not so. Par'o hardened his heart since (as Rav Hirsch explains in 14:5) it appeared that Bnai Yisrael "turned back" because Hashem could not defeat Baal Tzefon. Par'o was able to talk his people into chasing the Jews because they thought that Ba'al Tzefon could not allow them to defeat the "rabble" and return them to slavery. However, when it actually came down to chasing them into the sea, especially after the miracle of the cloud protecting the Bnai Yisrael all night and the sea splitting, the army should have remembered the plagues and the way Par'o begged the Bnai yisrael to leave, and defied Par'o and turned back. Had they done this, Par'o could not have done anything on his own. Therefore, the hearts of the Egyptians needed to be strengthened so that they would follow Par'o into the sea.