Buying and selling is not "my interpretation". It Nehemiah elaborates on this concept.
31And
if the people of the land bring ware or any victuals on the sabbath day to sell,
that we
would not buy it of them on the sabbath, or on the holy day: and
that we would leave the seventh year, and the exaction of every debt. Nehemiah 10: 31
Most people think that without the Rabbinic OCD list of creative work then we would all be lost and illiterate to Torah. Not true. Here are some valid Shabbat principals:
Of course it wasn't that difficult to define work during the days of ancient Israel. Work was laborious and difficult. Resting from this work was not something that needed to be detailed. Our common work today is much different though the principals are the same. I believe the most logical way to properly interpret "work" is based on occupation. This is a good starting ground for people turning to Torah and easy to understand.
The whole point of "not working" is meant to promote REST! Just look at the text:
Deuteronomy 5:12-14, "Keep the sabbath day to
sanctify it, as the LORD thy God hath commanded thee. Six days thou shalt labour, and do
all thy work: But the seventh day is the sabbath of the LORD thy God: in it thou shalt not do any work, thou, nor thy son, nor thy daughter, nor thy manservant, nor thy maidservant, nor thine ox, nor thine ***, nor any of thy cattle, nor thy stranger that is within thy gates;
that thy manservant and thy maidservant may
rest as well as thou."
Here is the Sabbath summed up. STOP WORKING AND FREAKING REST!
I find it humorous how difficult humans can make a simple command to rest.