In Exodus 31, the LORD declares what He has done in equipping certain Israelites to manage the building of the tabernacle and all its furnishings. He also reminds His people that the Sabbath rest must be faithfully observed during the construction.
Chapter 31 can be outlined as follows:
The LORD specifies which Israelites were to construct the Tabernacle and its furnishings.
The LORD gives a strong reminder that, in spite of their spiritual duty to build the tabernacle and the furnishings, the craftsmen are required to observe the Sabbath and cease their work. Anyone who did not observe the Sabbath would face dire consequences.
The LORD finishes speaking to Moses. This is most likely at the end of the forty days that Moses was in His presence on Mount Sinai.