In my work for Matthew 12 last week I had a think about Sabbath, what it looks like, and what Jesus is talking about in Matthew 12 with his grain-plucking disciples. (talk available here) Doing some work on the Hebrew word Shabbat - transliterated into English as Sabbath - yielded some interesting discussion on the primacy of either the verb or the noun.
The first time we meet the verb is in Genesis 2.2-3, where we hear that God shabbats after his 6 day creating week. He's done with his creating, now is time for his shabbat. When we talk about the Shabbat in Exodus 20, we find the verb accompanying is not shabbat but nuach - the verb 'to rest'. We also have a rich description of what is not to be done on that day - no one - human or animal, free or slave, is to do any work on that day. What they are to do is nuach - becaue that is what Yhwh did on the seventh day.
Where this gets interesting is that in some cognate languages the verb shabbat means not 'rest' or 'stop work' but 'celebrate the Sabbath'. The primary meaning is not to do with what is done - or should I say, not done - but with the day from whom the action (or inaction!) is named.
What the Pharisees have done is turn celebration and enjoyment of the creation God has made (one he also enjoys) into a regulatory nightmare, centering on what may not be done, so as to prohibit anything that might resemble 'work'.
What (I think) Jesus does in Matthew 12 with his 'the son of man is lord of the Sabbath' line is to explain that the very understanding of the word shabbat is wrong. It is and always has been about enjoying and resting in that joy, trusting that God is good and sovereign and trustworthy. There is no need for work, but a welcome into Sabbath rest - now for a day, but soon for eternity.