What is the significance of the fact that Hashem once again hardened Pharaoh's heart?
Ramban: Following Makas Bechoros, Pharaoh was terrified of Yisrael, and had not the least intention of chasing after them - even assuming they would flee, 1 in which case Moshe was free to do with them as he pleased. Consequently, Hashem had to harden his heart, to change his mind and chase after them. 2
What did Hashem mean when He said, "v'Ikavedah b'Pharaoh ... "?
Rashi: When Hashem takes revenge of the Resha'im, He becomes aggrandized and honored. 1
Rashi: See for example Tehilim 9:17 .
Why did Hashem make a point of first mentioning Pharaoh, and then his army?
Rashi: Because, since he was the first to sin, he would be the first to be punished.
Why does the Torah see fit to inform us that Yisrael turned back and encamped by the sea, as Hashem had commanded them?
Rashi: In order to demonstrate their praiseworthiness; in that they went back towards Egypt, and did not say, 'How can we go back towards our pursuers?' 1
Rashi: But rather they stated categorically 'We will only do what Moshe tells us.'
QUESTIONS ON RASHI
Rashi writes: "'And I shall be glorified through Pharaoh' - When Hashem exacts revenge upon the wicked, His Name is made great and glorified...." What does Rashi need to clarify here?
Gur Aryeh: We would assume that Hashem's Name is glorified most when He bestows goodness, by those who receive that goodness. Rashi explains that when Hashem takes revenge upon the wicked, everyone else in the world glorifies Him. 1
Maharal (Derech Chayim p. 168, to Avos 4:4): The Mishnah teaches, "[If] one profanes the Name of Heaven in secret, they exact payback from him in public." That is because "the entire world is the fullness of His Glory" (Yeshayah 6:3); such that this person's deed, despite being in private, has minimized that glory. The sinner's punishment is what restores Hashem's honor.
Rashi writes: "And they did so - In praise of [Yisrael], who obeyed Moshe...." Why this interpretation?
Gur Aryeh: It should go without saying that they followed Hashem's command! As Rashi explains, the Torah emphasizes that they did so, despite that logic would dictate that they flee from their pursuers. 1
Gur Aryeh also explains other instances in which the Torah tells us that "it was done as Hashem commanded."
Rashi writes that the Torah teaches the praise of Yisrael, that they accepted to do what Moshe said. But later they complained, "were there not graves in Egypt [that you needed to take us here to die]?!" (14:11)?
Moshav Zekenim, citing R. Moshe: The Erev Rav complained.
Moshav Zekenim: A Midrash says that they saw "Mitzrayim Nose'a Achareihem," i.e. the angel of Egypt coming to save Egypt (14:10) - then they despaired.
