In Parshas Vayakhel, why does the Torah describe the mishkan and keilim in such great detail, given that most of the information was already given in the previous parshiyos? Why didn't the Torah just write, in one verse, "And they made the mishkan and the keilim as HaShem told Moshe"?
Ralbag at the end of Sefer Shemos gives several thoughts as to why the Torah repeats the details of the vessels in the account of the mishkan's construction. The possibilities he considers are:
Abarbanel extends the third of the Ralbag's reasons in that since the order of construction was changed from the order of commandment (for whatever reason) one may have thought that other details may also have been changed from those given at the time of commandment to build. Because of this, the Torah elaborated on the details of what was constructed to show that they are the same as what was commanded to be constructed.
M. D. Cassuto, responding (as always) to the early Bible critics of his time, brings evidence to support Ralbag's first notion. That is, that in literature of the time period it was not uncommon to repeat the details of actions that have already been previously outlined. (Cassuto is also quoted, I think, by Nechama Leibowitz in her discussion on the topic.)