When the Torah narrates Moshe’s interactions with Paroh, the Torah describes how at various points in the story, God hardens Paroh’s heart, or Paroh does it himself.
By doing so, the story just dragged out.
The Seforno offers a compelling close reading.
There are two verbs the Torah uses to describe Paroh’s heart: heaviness and strength – כבד / חזק. Being strong is not a bad thing! For the first seven plagues – all uses of כבד are in reference to Paroh acting in such a way. Where Hashem acts directly, there is only חיזוק – Hashem gave him the strength to continue.
The key to understanding the Exodus story is to consider the end goal. It wouldn’t be hard to flatten Egypt with the proverbial lightning bolt, and it wouldn’t be hard to just airlift the Jews out. But instead, lots of other things happened that weren’t reducible to the goals of a defeated Egypt and a free Jewish People.
The story is very clear why, and it slips right under the radar. Hashem explicitly states the purpose of what is to come to Moshe, foreshadowing the first plague:
וְיָדְעוּ מִצְרַיִם כִּי-אֲנִי ה, בִּנְטֹתִי אֶת-יָדִי עַל-מִצְרָיִם; וְהוֹצֵאתִי אֶת-בְּנֵי-יִשְׂרָאֵל, מִתּוֹכָם – Egypt will know that I am the Lord, when I stretch My hand over Egypt, and take the Jews away from them. (7:17)
Having been conspicuously absent in the story up to now, Hashem wants to be recognized.
Having read this story a few times, our minds glaze over because we know it too well. At this point in the story, no one knows what God can do. Not Moshe, and certainly not Paroh. Even the Jewish People only knew they were descended from Avraham, Yitzchak, and Yakov; and that they believed in the One God of their ancestors. But that’s really it – no one knew God had actual power; no one had ever seen or heard of a miracle. Arguably, there hadn’t been a miracle since the Flood. So not without good reason, Paroh mocked Moshe:
מִי ה אֲשֶׁר אֶשְׁמַע בְּקֹלוֹ לְשַׁלַּח אֶת־יִשְׂרָאֵל לֹא יָדַעְתִּי אֶת־ה וְגַם אֶת־יִשְׂרָאֵל לֹא אֲשַׁלֵּחַ – Who is this Lord that I should heed Him and let Israel go?! I don’t know this Lord, and I won’t let Israel go! (5:2)
So when God flexed a strong and outstretched arm on Egypt, people would rightly be terrified. So Paroh needed strength – חיזוק. He could not free the Jews for the wrong reason; it could not be because Egypt was being toyed with. He needed strength to comprehend the nature of what he was facing.
After the 7th plague, the task is seemingly complete; and Paroh concedes, completely:
יִּשְׁלַח פַּרְעֹה, וַיִּקְרָא לְמֹשֶׁה וּלְאַהֲרֹן, וַיֹּאמֶר אֲלֵהֶם, חָטָאתִי הַפָּעַם: ה, הַצַּדִּיק, וַאֲנִי וְעַמִּי, הָרְשָׁעִים. הַעְתִּירוּ, אֶל-ה, וְרַב, מִהְיֹת קֹלֹת אֱלֹהִים וּבָרָד; וַאֲשַׁלְּחָה אֶתְכֶם, וְלֹא תֹסִפוּן לַעֲמֹד – Paroh sent for Moshe and Ahron, and said to them, “Now I have sinned. Hashem is righteous; my people and I are guilty. Beg the Lord to bring an end to this flaming hail; I will free you; you will be here no longer…” (9:27,28)
Mission accomplished, and Egypt has been educated. With three more plagues to come, Hashem tells Moshe the student to be educated has changed:
וּלְמַעַן תְּסַפֵּר בְּאָזְנֵי בִנְךָ וּבֶן-בִּנְךָ, אֵת אֲשֶׁר הִתְעַלַּלְתִּי בְּמִצְרַיִם, וְאֶת-אֹתֹתַי, אֲשֶׁר-שַׂמְתִּי בָם; וִידַעְתֶּם, כִּי-אֲנִי ה – So that you tell over to your sons and daughters how I toyed with Egypt, with my wonders that I cast on them, and you will know that I am the Lord. (10:2)
Now it is about the Jews.
The Jews needed to understand what Hashem would do for them. It was understandably mind-bending for them to comprehend what was taking place, and they fought a life of miraculous redemption the rest of their days. But even if that generation wouldn’t see it, their children would.
God cares about the slaves. God cares about the victims. God cares about us all. And God will do something about it.