There is a lot in this short chapter: Firstly we see that the Holy Spirit fills Bezalel (v.3). God's Spirit is not mentioned that often in the Old Testament (and this is his first mention in Exodus), and when the Spirit fills someone in the Old Testament it is normally for a specific purpose - unlike after Pentecost when the Spirit fills all God's people permanently. So Bezalel (who was not a king or a priest but a 'mere' artisan) was singled out for very special blessing - but one which today we can all receive.
The work which Bezalel does is a mini version of what God did in creation - just as the Tabernacle can be seen as a mini version of creation - and just as the kind of words used of Bezalel in v.3 are also the kind of words used in the Bible to describe God's work of creation.
So perhaps it is no surprise that, just as God rested on the seventh day of creation, so God now re-emphasises the importance of resting on the seventh day. The wording in v.15 is very strong, and repeats what we have already been told in chapters 20 and 23 (and will be told again in chapter 35).
So, just to be clear (Exodus says), the work Bezalel does on the Tabernacle is important - but it is not important enough to excuse breaking the Sabbath. If he did that, it would be as if he were saying he was better than God - because even God took a rest and made the Sabbath day holy.
For some people, the primary temptation is to rest when they should be working. But the Bible seems to recognise that for most of us, the temptation is the other way round. Exodus keeps ramming home the point: as far as God is concerned, there are no valid excuses for working when we should be resting.
Questions to ponder: What excuses do you make for working when you should be resting? How can you make sure you set aside time to be with God (rather than only doing things for God)?