Parshat Ki Tisa
In 31:13 it says about Shabbos that it is a sign "Between Me and you... that I have made you holy (separate)".
In 31:17 it says about Shabbos that "Between Me and Israel it is a sign forever.."that I created the world in 6 days and on the 7th day I rested".
So what is Shabbos a sign for? That God rested on the 7th day or that the Jews are a holy and separate nation?