The three main references to Shabbat in the Torah are:

Genesis 1:31-2:3


The sixth day. So the heavens and the earth were finished, with all their complement. On the seventh day, God had completed His work which He had undertaken, and He rested on the seventh day from all His work which He had been doing. Then God blessed the seventh day and made it holy, because on it He ceased from all His creative work, which God had brought into being to fulfill its purpose.

Exodus 20:8-11

Remember Shabbat to keep it holy. You should labor for six days and do all your work, but the seventh day is Shabbat for the Lord your God. You may not do any creative work — neither you, your son, your daughter, your male or female worker, your animal, nor the stranger who dwells among you. Because it was in six days that God made the heavens and the earth, the sea and all that they contain, and He rested on the seventh day.

Exodus 31:16-17


The children of Israel should keep Shabbat, observing Shabbat throughout their generations, as an everlasting covenant. It is a sign between Me and the children of Israel forever, that in six days God made the heavens and the earth, and that on the seventh day He was finished and He rested.