“Just as the LORD had commanded Moses” is the theme of Exodus 39 & 40. Nothing “new” was commanded here; rather the focus was on how Moses actually DID everything that God had commanded him. Notice how these same words, “just as the Lord had commanded Moses” are repeated in all of these verses:
We see that phrase in verses 1, 5, 7, 21, 26, 29, and 31. Then :32 gives a summary which says: “and the sons of Israel did according to all that the LORD had commanded Moses; so they did.” And :42-43 give a second summary: “So the sons of Israel did all the work according to all that the LORD had commanded Moses. And Moses examined (saw) all the work and behold, they had done it; just as the LORD had commanded, this they had done. So Moses blessed them.”
The point is, Moses and the people DID just as God commanded them regarding the articles for the tabernacle, in every case. For example, in Exodus 28:6 God commanded “They shall also make the ephod of gold, of blue and purple and scarlet material and fine twisted linen, the work of the skillful workman.” Then here in 39:2 it says: “He made the ephod of gold, and of blue and purple and scarlet material and fine twisted linen.” It was indeed done, “just as the LORD had commanded Moses” — word for word! And so throughout the text. What God told them to do, is exactly what they did.
The lesson for us could not be more plain. We too are to do “just as the LORD has commanded” US in His word. Moses & the people were not to “adapt” or change anything God had shown them. It would have been the height of arrogance for them to say: “Well, we think we won’t fold this breastpiece double” (:9) or whatever. NO! That would have been a flagrant sin against God.
If so, then why would WE think we can change God’s commands today? No, our commitment and practice needs to be just like that of Moses and the people here: in everything we too are to do “just as the LORD had commanded.”