This chapter has to do with the consecration of the priests and of the Tabernacle. When it says “all the congregation,” it means the entire nation was to assemble there. The Hebrew word for “congregation” is edah.
This chapter tells of the setting up of the Tabernacle and the annointing of the priests.
This chapter continues the construction. The construction of Altar of Burnt Offering, the Laver, and other materials of the Tabernacle are discussed.
Bezalel and Oholiab were apparently in charge of the skilled craftsmen who performed the construction.
This chapter is mostly a repetition of the previous commands given. The previous commands started with the holiest of the objects, starting with the Ark of the Covenant, and working outward. But here the construction of the Tabernacle itself and then continues with the furnishings. It is very practical. First build the house, then you have a place to put the furnishings as you construct them.
Since the convenant has been re-instituted, the Tabernacle may now be built. The instructions were given in earlier chapters, but the construction had not yet taken place.