The supposed pretense for the departure of Moses' people from Egypt is given by two fragments of the Priestly source,1,2 in which the pharaoh had enslaved the people, subjecting them to all manner of hardships, even to the point of ordering the deaths of all of the baby boys. Such would certainly constitute sufficient reason for wanting to flee the country. After the 10th Plague, the pharaoh finally granted the leave, but then he changed his mind, and sent the army after the people,3 supposedly to bring them back to continue the oppression. So it sounds like the pharaoh would have used any means at his disposal to dominate the people, and only lost them to the superior powers of YHWH. But Elohist passages written earlier prophesied that the pharaoh would deliberately drive Moses' people out of Egypt, and with a strong hand at that.4,5 So which was it — was the pharaoh deliberately trying to keep the people enslaved in Egypt, or was he deliberately trying to force them out, against their wish to stay? To answer that, we'll have to read the scriptures carefully, and then fill in the blanks with secular history.
Moses told the pharaoh many times to let the people go, which sounds like a demand that they be freed from slavery as mentioned just above. But when Moses elaborated on the demand, he made no mention of moving to Canaan — he just wanted permission to lead the people into the wilderness for a religious festival.
Then Pharaoh called Moses and Aaron and said, "Go, sacrifice to your God within the land." But Moses said, "It would not be right to do so, for the offerings we shall sacrifice to the Lord our God are an abomination to the Egyptians. If we sacrifice offerings abominable to the Egyptians before their eyes, will they not stone us? We must go three days' journey into the wilderness and sacrifice to the Lord our God as he tells us."
Then Pharaoh's servants said to him, "...Let the men go, that they may serve the Lord their God..."
The real issue here was not slavery, but religious persecution. If the year was , the people being oppressed would have been Atenists, and their leader would have been a high priest from Amarna, such as Moses. So the request was for permission to hold an Atenist festival in the wilderness, where no one would be offended by their practices. Moses specifically stated that it would take three days to get there. The destination was Etham, near modern Ismaïlia, which could be reached on foot in three days, being 130 km from Memphis, and just 80 km from Avaris. (Average hiking speed is 5 km/hr, so if they hiked for 8 hours a day, in 3 days they would travel 120 km.) But they picked the wrong place to go if the intent was to hold a festival with no one else around — Etham was on the ancient Suez Canal, which was a busy place. The destination might have had more to do with politics than privacy. The canal served as the border of Egypt, and the ban on Atenism didn't apply in the provinces (such as the Sinai, the Negev, and Canaan) where the pharaoh exercised looser control. So if they crossed the border at Etham, they would be able to have an Atenist festival without breaking the law. And when the pharaoh finally granted the permission, that's exactly what they did.6,7
Curiously, after the festival they turned around and headed back.8 Why would they head back? It's possible that the intent was just to hold a festival. In other words, moving to Canaan wasn't mentioned, so that wasn't why the people headed to Etham — they hiked 3 days to attend the festival, with the intent of returning to their homes in Egypt as soon as it was over.
Of course, that isn't how it worked out. Once on the way back, they looked up and saw the pharaoh's army.
5 (J) When the king of Egypt was told that the people had fled, the mind of Pharaoh and his servants was changed toward the people, and they said, "What is this we have done, that we have let Israel go from serving us?" 6 (J) So he made ready his chariot and took his army with him, 7 (J) and took six hundred chosen chariots and all the other chariots of Egypt with officers over all of them. 8 (P,E) And the Lord hardened the heart of Pharaoh king of Egypt, and he pursued the people of Israel while the people of Israel were going out defiantly. 9 (E,P) The Egyptians pursued them, all Pharaoh's horses and chariots and his horsemen and his army, and overtook them encamped at the sea, by Pi-hahiroth, in front of Baal-zephon.
The conventional interpretation is that the pharaoh deployed the army to capture Moses' people and bring them back to Egypt. But that isn't what it says — it just says that when the pharaoh learned that the people had left, he changed his mind, and sent the army after them. Another possible interpretation, more consistent with the confrontation occurring after the Atenists had turned back, is that the pharaoh changed his mind about letting them return.
If the year was , this wouldn't be hard to understand. Horemheb had outlawed Atenism. Anybody continuing in the worship of the Aten would have gone underground. Perhaps Horemheb wanted to get rid of those people, but he wouldn't have even known who to target. We know that the decision was to give the Atenists time off for a religious festival. This would have served Horemheb's first objective — only the adamant Atenists would have made the three-day hike out of devotion to the Aten, so he would have learned the identity of his adversaries. Second, if he could figure out a way of preventing the fanatics from coming back, the more moderate Atenists still in Egypt would have been a lot more manageable. So how was he going to do that? Deploy the army. With the road back to Egypt blocked, and with nothing but desert in the other direction, and having brought provisions just for a festival — not for a trek across the Sinai — the Atenists were caught in a deadly trap.
11 (E) They said to Moses, "Is it because there are no graves in Egypt that you have taken us away to die in the wilderness? What have you done to us in bringing us out of Egypt? 12 (E) Is not this what we said to you in Egypt: 'Leave us alone that we may serve the Egyptians'? For it would have been better for us to serve the Egyptians than to die in the wilderness."
Ah, but their fears were premature, because they did not die (at least not on that day). Rather, the Lord fought on their side against the Egyptian army,9 who then fled when they realized that the Lord was with the Atenists.10 It's odd to hear the army fearing the god of their adversaries. This reads a bit easier if it's a reference to the god that the Egyptian army did respect — the pharaoh. So this would have been the Lord Horemheb fighting his own army on behalf of the Atenists. Why? Look at the whole situation from Horemheb's perspective. He wanted to get rid of the adamant Atenists, but if he had ordered the army to massacre them, it would have enraged the moderate Atenists still in Egypt, renewing the problem that he was trying to solve. So instead, he pretended to be their champion, willing to fight against his own army to protect them. In other words, he positioned the army as hard-liners who wanted to destroy the Atenists, with himself standing in the way. Still, once any blood at all had been drawn, there wasn't any going back for the Atenists, even if it was only a skirmish, and a staged one at that.
Next we hear that the Lord led the people in the direction of the Promised Land, with a cloud (i.e., smoke) by day and fire by night.11 If this was the Lord Horemheb, he personally led the Exodus,12 though it might have been more of a supervised suicide march than a liberation — in the wilderness, the Atenists died of hunger and thirst,13,14 not to mention the toll taken by the plague,15,16 and by battles with hostile tribes.17,18,19,20,21 This is consistent with a pharaoh who wanted to get rid of them, as long as the blame wasn't going to stick to him — if it was too politically awkward to suppress the Atenists with brute force, he could just let the desert do his dirty work. And it makes sense that the Lord led the people by three days' march — the Lord Horemheb travelled ahead of the main camp, to arrange the booby-traps.
With all of that as the outcome, we can wonder when the conniving actually began. The wilderness festival might have been Horemheb's idea, since it served his purposes, and not those of the Atenists. But Horemheb's strategy might have begun earlier. In the Torah, it took 10 Plagues to convince the pharaoh to let the people go, making it sound like Horemheb was forced into the concession. Yet the 10 Plagues served his purposes as well. If the plan was to do away with prominent, popular members of the community, it would have been to his advantage to first turn that community against them. If some of the Plagues were acts of civil disobedience on the part of the Atenists, but which hurt everyone, the popularity of the Atenists would have waned. And every time a plague hit the rest of the Egyptians, but spared the Atenists (i.e., the 4th, 5th, 7th, 9th, and 10th Plagues), resentments would have multiplied. After the 10th Plague (i.e., the death of the first-born), the populace begged the Atenists to leave, even offering silver & gold as incentives...
33 (E) The Egyptians were urgent with the people to send them out of the land in haste. For they said, "We shall all be dead." 34 (J) So the people took their dough before it was leavened, their kneading bowls being bound up in their cloaks on their shoulders. 35 (J) The people of Israel had also done as Moses told them, for they had asked the Egyptians for silver and gold jewelry and for clothing. 36 (J) And the Lord had given the people favor in the sight of the Egyptians, so that they let them have what they asked. Thus they plundered the Egyptians.
This introduces the possibility that Horemheb wasn't actually forced into letting the people go — he might have orchestrated the acts of civil disobedience, just as Nero might have burned Rome so that he could blame it on the Christians.
One can only imagine how all of this looked from the perspective of the Atenists. They didn't think that they had done anything wrong. During the reign of the Amarna pharaohs, they had been loyal citizens, and had learned to worship the Aten, just as the pharaohs had ordered. After Tutankhamun restored the status of the Amun priesthood, it was still legal to worship the Aten, even if it was then also legal to worship the other gods in the Egyptian pantheon. Some of the people would have continued in the worship of the Aten, while others would have gone back to worshiping Ra, Osiris, Amun, etc. Then, all of a sudden, Horemheb outlawed Atenism altogether. Most of the people would have complied, but somebody in their midst started organizing acts of civil disobedience, some of which targeting non-Atenists (especially the 10th Plague). This would have been a good time to at least pretend to be an Atenist, if only in the interest of protecting one's first-born during Passover. But it came at a cost — after the 10th Plague, the rest of the community was willing to do anything to get the Atenists to leave. The wilderness festival turned out to be a trap, and the trek toward the "Promised Land" turned out to be a supervised suicide march. No wonder they complained bitterly.
Finally, we can wonder whether or not Moses was a witting accomplice in the conniving. There isn't any evidence that he was anything but a sincere advocate of the new faith. Furthermore, he would have had no reason to knowingly participate in the attempted destruction of Atenism. His political career in Egypt was already finished, and he had already been exiled to Moab when Tutankhamun abandoned Amarna in . Doing a favor for Horemheb like this wasn't going to garner him any stature in Egypt. And he was 70 years old in , an age at which a man has few ambitions, except to see his legacy preserved. We can only conclude that Moses saw the 1312-Exodus as a chance to reinforce his camp on the East Bank, that those hearty enough to make the journey would pass the stories on to their children. And so they did.