אור החיים — ויקהל משה... ששת ימים תעשה מלאכה

Q — Why does Moshe preface the construction of the Mishkan with the command of Shabbat, and what are 'these things (אלה הדברים) that God commanded to do' in the opening verse?

A — Or HaChaim joins Rashi, Ibn Ezra and Ramban in the conclusion that placing Shabbat first teaches that the building of the Mishkan — even though it is sacred 'heavenly work' — does not override Shabbat. Precisely because one might have thought such holy labor should push aside Shabbat, Moshe warned: 'even though you are obligated in heavenly work, take care not to do labor on Shabbat.' This also resolves the phrase 'אלה הדברים': they are the categories of melacha forbidden on Shabbat that the Mishkan's construction defines.