Soon, though, the wear of daily life in the desert begins to show. The people complain of hunger and are given manna. The people complain of thirst and Moses is told by God to strike a rock, causing a spring to flow from it. The portion ends with the war between Israel and Amalek.
In Exodus 14:5, the Egyptians realize that the Israelites have fled, and in dismay they begin to chase them. The Egyptians' reaction is somewhat surprising, given that in Exodus 12:33 they could not hustle the Israelites out of their country fast enough.
Rabbi Shlomo ben Yitzchak (Rashi), the pre-eminent medieval commentator, explains that while the Egyptians certainly knew of the Israelites' departure, they had expected them to be gone for only three days, since that was the length of time Moses had requested for a religious pilgrimage. Only after the three days had passed without the Israelites returning did the Egyptians realize their slaves were really gone.
All of this brings up a question very much at the heart of the exodus story. Why is it that Moses and Aaron consistently ask Pharaoh to allow the Israelites three days in the wilderness to worship God? Why not ask for outright freedom?
Time after time, throughout the 10 plagues, throughout the vicissitudes of Pharaoh's broken promises, Moses' and Aaron's request remains constant: "Let us go a three days' journey into the wilderness and sacrifice to the Lord our God." If their goal was the ultimate emancipation of God's people, why not be up front about their motives? Why shroud this pivotal moment of national freedom in the murkiness of deception? They debate with Pharaoh about who will be allowed to come along and what they will bring, but the substance of their petition is always a three-day pilgrimage.
Some have suggested that Moses requested a three-day journey because had he requested ultimate freedom, Pharaoh would certainly have refused. Rabbi Abraham Ibn Ezra claims that it was important to phrase the request as a three-day journey so that the Egyptians would chase after the Israelites when they did not return, causing the Egyptians to meet their final punishment at the Red Sea. Ibn Ezra adds that Moses and Aaron do not actually lie, in that they never say that the Israelites will return after the three-day journey.
I would like to suggest an alternate reading, in which the three-day request has nothing to do with the Egyptian reaction. Instead, I believe that phrasing the request as a three-day journey was specifically designed to accommodate the children of Israel.
A people enslaved for hundreds of years could not imagine anything as sweeping as complete freedom. It was difficult enough to believe that they could have three days free from the unceasing demands of their overseers, three days where their only responsibility would be to serve God. Indeed, after generations under the absolute control of cruel masters, the ability to imagine oneself in lone and independent contemplation of God for three days is almost the same as contemplating eternal freedom.
When the Israelites leave Egypt, they do not realize that it is a permanent departure. It is only once the Israelites find themselves alone in the wilderness, no longer hounded constantly by their Egyptian masters, no longer surrounded by the trappings of slavery, that they can see to the next step and understand that they will be ultimately and truly free.
There in the desert they can sing exultant songs to God marking their redemption and also looking forward to their future in the Promised Land.
Yet no transformation this large can be accomplished in a matter of days. Time in the desert opens the Israelites' horizons of expectations, but it cannot erase their Egyptian past. In the second half of the portion, as the people weary of desert life, they complain, "Would that we had died by God's hand in the land of Egypt where we sat on meat pots and ate bread to satiety" (Exodus 15:3). This complaint is echoed many times in the course of that generation's travels. In the end, it is only their children, the second generation, who are truly able to leave Egypt behind and make their way to the land of Israel.
Radical changes in thinking and perspective are difficult and must evolve gradually. The Israelites cannot really contemplate complete freedom while they are enslaved in Egypt. The most they can imagine is a three-day furlough in which they as independent beings can worship God. Once they are in the wilderness, their thinking expands and they can begin to envision a future of complete freedom.
It is not until the next generation, though, that a true exodus in which Egypt is finally left behind, can occur.