Exodus is usually remembered for its first fifteen chapters, and its own proportions disagree. Slavery, the call at the burning bush, the contest with Pharaoh, the plagues and the sea take up rather less of the book than the instructions for building a tent. Chapters 25 to 31 specify the tabernacle in exhaustive detail, and chapters 35 to 40 describe it being built, repeating the specification almost clause for clause. Thirteen chapters on a portable sanctuary is more than the plagues get.
That imbalance is the argument of the book. The going out is not the destination. Israel leaves Egypt in chapter 15, arrives at Sinai in chapter 19, and never leaves it: the whole second half happens at one mountain. What is established there is a covenant, a body of law, and a structure built so that the divine presence has somewhere to be in the middle of an encampment. The last verses of the book are the cloud settling on the tent, and the narrative simply stops there, because that is the point it has been travelling towards.
Between the instruction and the building sits the golden calf, which is not a digression. Israel breaks the covenant before the ink is dry, the tablets are smashed, and the tablets are cut a second time. Placing that failure in the gap between the plan and its execution means the sanctuary that eventually goes up is a second attempt, occupied by a presence that has already been given cause to leave. Every later Israelite institution reads itself through that sequence.