Almost half the book of Exodus is taken up with descriptions of the building of the Tabernacle, mishkan, but much of it is repetitive and does not seem to provide any additional information. Things that are dear to us, the Ramban explains, we dwell on, discuss and repeat. The mishkan was an example of the people, every man and woman whose heart urged them, volunteering to build a home for Hashem. To show us how dear this was to God, the Torah spends time telling and retelling this story.