One may wonder why it took so long to take the Jews out of Egypt. After a clear decision to redeem them, numerous warnings and plagues, the Jews finally exited, only to be chased by Pharaoh and the Egyptian army regretful of their decision and looking to recapture their freed slaves.
Why did Hashem not expedite the entire Exodus process? Certainly, Hashem was capable of freeing them more quickly. Moreover, Hashem was clearly interested in performing miracles, as seen by both the many he performed as well as informing Moses of his plan to redeem the Jews via great miracles (Shemot 6:6-9). Once He was willing to do that, why not miraculously redeem them instantaneously? Why drag it out for so long?
A clear indication that there was no rush to take the Jews out is that Hashem hardened Pharaoh’s heart, ensuring a longer enslavement and greater amount of time spent in Egypt. Hashem was clearly interested in the Jews remaining there until the end of plagues. Why?
Apparently there was an additional agenda besides redeeming the Jews, but what was it?
Perhaps we can make two suggestions. Firstly, the Rambam (Teshuva 6:3) explains that the Egyptians treated the Jews so harshly that justice demanded that they receive extra punishment. Hashem removed Pharaoh’s free-will ensuring a slower Exodus in order to properly punish Pharaoh.
However, there may have been a second divine agenda. Hashem may have wanted the Egyptians to recognize His uniqueness and divinity (See Ramban on Shemot 10:1).
There are several supports to this theory. Firstly, there seems to have been some tension between Moses and Pharaoh regarding the obligation to listen to Hashem’s word. After being asked to free the Jewish slaves, Pharaoh replies, “I do not know Hashem and also, I will not send them out” (Shemot 5:2). Pharaoh does not recognize Hashem, but even if he would, he does not view Hashem’s word as binding. Perhaps the Chumash (Pentateuch) records Pharaoh’s attitude precisely because it the attitude that needs to be corrected.
Additionally, Moses instructs Pharaoh to “Send my people” (Shemot 7:16, 8:16, 9:2, 9:13) not “Let them go.” Having Pharaoh send the Jews, opposed to simply allowing them to leave, further reflects this second aim, Pharaoh losing and admitting to Hashem’s role as the divine being to whom all must listen.
Furthermore, and perhaps clearest, the Torah itself testifies numerous time (8:6, 8:18, 9:29-30, 10:1, 11:7) that the goal of the Makkot was to educate the Egyptians.
This theory can also explain why so many (if not all) of the plagues, Makkot, undermined the authority of the Egyptian gods including the Karban Pesach (Pascal Lamb), the killing of the lamb, the Egyptian god (Shemot Rabbah 16:2 and Ramban on Shemot 12:3).
Although there had been signs of Egypt slowly progressing to accept Hashem’s Divine rule (Shemot 8:15, 9:27, 10:16, 11:3 and Ramban there), it is at the Reed Sea, Yam Suf, the Egyptians actually realize who Hashem is and declare that “Hashem is fighting for them!” If this answer is really correct, and elongating the Exodus was designed to facilitate the educational process for the Egyptians, a major question has to be asked. Why kill the Egyptians immediately after the genuinely recognize who Hashem is? Does that not undermine the entire educational process?
Perhaps the Egyptians’ understanding and accepting Hashem’s uniqueness is not the goal in it of itself, but rather a means towards a greater end. Having witnessed the aristocratic culture and kingship accept Hashem sets the foundation for the Jews to build their faith. After all, it is precisely the Egyptians’ recognition of Hashem that enables the Jews to accept Him, for only after the Jews witness the Egyptians accept Hashem and then lose to him, does the Torah testify “And they accepted Hashem and Moses his servant” (Shemot 14:31). After having seen the Reed Sea events, the Egyptians have served their purpose and there is no longer a need to elongate the Exodus. It is precisely then when Hashem ends the procrastinating and gives them their final punishment.
Moreover, the goal may not just have been to convince the Egyptians and even the Jews of that generation. The Torah uses the Exodus as a paradigm of Hashem's involvement (Ramban on Shemot 13:16) in the world as a story to tell and retell for generations (Shemot 10:2).