(21) Then Moses held out his arm over the sea and the LORD drove back the sea with a strong east wind all that night, and turned the sea into dry ground. The waters were split, (22) and the Israelites went into the sea on dry ground, the waters forming a wall for them on their right and on their left. (23) The Egyptians came in pursuit after them into the sea, all of Pharaoh’s horses, chariots, and horsemen.
(ג) וְאֶפְשָׁר שֶׁיֶּחְטָא אָדָם חֵטְא גָּדוֹל אוֹ חֲטָאִים רַבִּים עַד שֶׁיִּתֵּן הַדִּין לִפְנֵי דַּיַן הָאֱמֶת שֶׁיְּהֵא הַפֵּרָעוֹן מִזֶּה הַחוֹטֵא עַל חֲטָאִים אֵלּוּ שֶׁעָשָׂה בִּרְצוֹנוֹ וּמִדַּעְתּוֹ שֶׁמּוֹנְעִין מִמֶּנּוּ הַתְּשׁוּבָה וְאֵין מַנִּיחִין לוֹ רְשׁוּת לָשׁוּב מֵרִשְׁעוֹ כְּדֵי שֶׁיָּמוּת וְיֹאבַד בְּחֶטְאוֹ שֶׁעָשָׂה. הוּא שֶׁהַקָּדוֹשׁ בָּרוּךְ הוּא... כְּלוֹמַר חָטְאוּ בִּרְצוֹנָם וְהִרְבּוּ לִפְשֹׁעַ עַד שֶׁנִּתְחַיְּבוּ לִמְנֹעַ מֵהֶן הַתְּשׁוּבָה שֶׁהִיא הַמַּרְפֵּא. לְפִיכָךְ כָּתוּב בַּתּוֹרָה (שמות ד כא) "וַאֲנִי (אֲחַזֵּק) [אַקְשֶׁה] אֶת לֵב פַּרְעֹה". לְפִי שֶׁחָטָא מֵעַצְמוֹ תְּחִלָּה וְהֵרֵעַ לְיִשְׂרָאֵל הַגָּרִים בְּאַרְצוֹ שֶׁנֶּאֱמַר (שמות א י) "הָבָה נִתְחַכְּמָה לוֹ". נָתַן הַדִּין לִמְנֹעַ הַתְּשׁוּבָה מִמֶּנּוּ עַד שֶׁנִּפְרַע מִמֶּנּוּ. לְפִיכָךְ חִזֵּק הַקָּדוֹשׁ בָּרוּךְ הוּא אֶת לִבּוֹ. וְלָמָּה הָיָה שׁוֹלֵחַ לוֹ בְּיַד משֶׁה וְאוֹמֵר שְׁלַח וַעֲשֵׂה תְּשׁוּבָה וּכְבָר אָמַר לוֹ הַקָּדוֹשׁ בָּרוּךְ הוּא אֵין אַתָּה מְשַׁלֵּחַ שֶׁנֶּאֱמַר (שמות ט ל) "וְאַתָּה וַעֲבָדֶיךָ יָדַעְתִּי" וְגוֹ' (שמות ט טז) "וְאוּלָם בַּעֲבוּר זֹאת הֶעֱמַדְתִּיךָ". כְּדֵי לְהוֹדִיעַ לְבָאֵי הָעוֹלָם שֶׁבִּזְמַן שֶׁמּוֹנֵעַ הַקָּדוֹשׁ בָּרוּךְ הוּא הַתְּשׁוּבָה לַחוֹטֵא אֵינוֹ יָכוֹל לָשׁוּב אֶלָּא יָמוּת בְּרִשְׁעוֹ שֶׁעָשָׂה בִּתְחִלָּה בִּרְצוֹנוֹ.
(3) And, it is possible that a man should commit either one grievous iniquity or a multitude of sins so that the Judge of Truth will decree against him that, whereas this sinner committed those sins of his own free will and consciously, repentance should be witheld from him altogether, and grant him no leave to repent, so that he might die and perish in the iniquity he committed... It is, therefore, written in the Torah; "And I will harden Pharaoh's heart" (Ex. 14.4), because at the beginning he sinned of his own free will, and meted out evil to Israel who sojourned in his land, even as it is said: "Come, let us deal wisely with them" (Ibid. 1.10). Thereat justice demanded to withold repentance from him, so that due punishment might be visited upon him. Wherefor, the Holy One, blessed is He! hardened his heart. If it be so, then why did He delegate Moses to him, charging him to let Israel go forth and turn to repentance seeing that the Holy One, blessed is He! long since told him thou wilt not let them go forth, saying: "But as for thee and thy servants, I know that ye will not yet fear the Lord God" (Ibid. 9.30), and again saying: "But in very deed for this cause have I made thee to stand, to show thee My power, and that My name be declared throughout all the earth"(Ibid. –16)? To demonstrate to the future generations whenever the Holy One, blessed is He! witholds repentance from a sinner he can not repent, but must die in the original evil which he perpetrated of his own free will.
(1) ואני אקשה AND I WILL ALLOW [PHARAOH’S HEART] TO HARDEN — Since he has wickedly resisted Me, and it is manifest to Me that the heathen nations find no spiritual satisfaction in setting their whole heart to return to Me penitently, it is better that his heart should be hardened in order that My signs may be multiplied against him so that ye may recognise My divine power. Such, indeed, is the method of the Holy One, blessed be He: He brings punishment upon the nations so that Israel may hear of it and fear Him, as it is said, (Zephaniah 3:6, 3:7) “I have cut off nations, their corners are desolate etc. … I said: Surely thou wilt fear Me, thou wilt receive correction” (cf. Yevamot 63a). Nevertheless, in the case of the first five plagues it is not stated, “The Lord hardened Pharaoh’s heart” but “Pharaoh’s heart was hardened” (Midrash Tanchuma, Vaera 3).
והנה פירשו בשאלה אשר ישאלו הכל, אם השם הקשה את לבו מה פשעו, ויש בו שני טעמים ושניהם אמת.
האחד, כי פרעה ברשעו אשר עשה לישראל רעות גדולות חנם, נתחייב למנוע ממנו דרכי תשובה, כאשר באו בזה פסוקים רבים בתורה ובכתובים, ולפי מעשיו הראשונים נדון.
והטעם השני, כי היו חצי המכות עליו בפשעו, כי לא נאמר בהן רק ויחזק לב פרעה (להלן פסוק יג, כב, ח טו), ויכבד פרעה את לבו (להלן ח כח, ט ז). הנה לא רצה לשלחם לכבוד השם, אבל כאשר גברו המכות עליו ונלאה לסבול אותם, רך לבו והיה נמלך לשלחם מכובד המכות, לא לעשות רצון בוראו. ואז הקשה השם את רוחו ואמץ את לבבו למען ספר שמו…
Nahmanides Gloss on Exodus 7:3
I will answer the question that all who read this narrative are want to ask; “If God hardens Pharaoh’s heart what is his sin?” There are two reasons both of which are true.
The first reason is that Pharaoh, in his wickedness, committed unwarranted acts of evil against Israel. As a result, his ability to repent was removed. There are many verses in Scripture that suggest that one can be judged by one’s earlier actions.
The second reason is that his sin was his unwillingness to liberate Israel resulting in the first five plagues, where it only says, “Pharaoh’s heart was stiffened,” or “Pharaoh’s heart was hardened.” This exhibits that he did not want to liberate Israel to honor God. However, when the plagues intensified and he began to suffer from them, his heart was softened and he was wont to free them because of the plagues and not in recognition of divine will. At that point, God hardened his spirit and strengthened his heart in order to make His name known…
The Wickedness of Egypt: Spiritual Slavery in the Land of Pharaoh, Daniel Crane
...this reading presents a challenge: if Egypt is completely under the control of Pharaoh, how can the Egyptians deserve the punishments delivered upon them? The wisdom of the rabbis whose work makes up Exodus Rabbah teaches that the Egyptians were indeed an evil people and that God's justice is not impugned in their suffering through the plagues. Still, if Egypt is already evil, why would Pharaoh's power play a role in their actions? It stands to reason that God's breaking of Pharaoh's power over the people is intended to have an effect; yet if the people are evil one way or another, this effect is diminished. Thus, there must be some good in the Egyptian people or else they would not be worth saving from Pharaoh's power. Perhaps then we are to understand Egypt's evil as a willing enslavement to Pharaoh's will.
So it is that the story of the Exodus from Egypt ends with the death of the Egyptians. Although the text does not state that they were an idolatrous people, their unwavering association with Pharaoh's evil will characterizes them as worshipers of him. God attempts to save them from their idolatry by revealing Godself through the plagues. However, Egypt ignores the signs and wonders that God manifests, continuing their self-destructive commitment to a man who has no regard whatsoever for their well-being. By not "slaying the gods of Egypt and preparing the Passover" (E.R. XVI.2), the Egyptians consign themselves to the fate that otherwise would have awaited the Israelites. Because of Egypt's blindness to God and unquestioning obedience to an entirely evil man, the people of Egypt prepare themselves for retribution. This retribution is delivered in one stroke of freedom and destruction as the walls of the Sea of Reeds and the blinders of the Egyptian people simultaneously and disastrously come crashing down.
Rabbi David Horwitz (Rosh Yeshiva at Yeshivat Rav Yitzchak Elchanan)
The gemara (Arakhin 10b) explains that one does not say full Hallel each day of Pesach because, unlike Sukkot, the sacrifice on each day of the Pesach is the same. The Taz (490:3) quotes a midrash which provides a different reason. One may not recite Hallel, according to the Taz, because God objected: "Ma'asei yadai tove'im ba-yam, ve-atem omerim shira?" "My handiwork is drowning in the sea, and you would recite song?"
This supplements the well-known gemara (Megilla 10b and Sanhedrin 39b): "The Holy One, Blessed be He, does not rejoice over the fall of the wicked."
The 19th century-commentator R. Ya'akov Ettlinger, (Arukh le-Ner), amplifies the statement in Sanhedrin by pointing out that, as Jews are commanded to follow in God's ways, (imitatio Dei; ve-halakhta bi-derakhav), Hashem's attitude must shape, and determine our own attitudes. The gemara (ad loc.) continues with the statement that when the angels wanted to sing at Yam Suf, Hashem did not allow them to do so. "In that hour the ministering angels wished to utter the song (of praise) before the Holy One, Blessed be He, but He rebuked them, saying: "My handiwork (the Egyptians) is drowning in the sea; would you recite song before me?"
Pesikta de- Rav Kahana (ed. S. Buber, p. 189a):
"Why does Scripture give no [explicit] command to rejoice during Pesach? Because the Egyptians died during Pesach. And similarly do you find that although we read the [entire] Hallel on each of the seven days of Sukkot, on Pesach we read the entire Hallel only on the first day and on the night preceding it. Why? Because of what Shemuel would quote: "Bi-nefol oivekha al tismach" - "Do not gloat at the fall of your enemy." (Proverbs 24:17).