Genesis 2:2-3

And by the seventh day God completed His work which He had done, and He rested (ceased) on the seventh day from all His work which He had done. [Heb 4:9, 10] So God blessed the seventh day and sanctified it [as His own, that is, set it apart as holy from other days], because in it He rested from all His work which He had created and done. [Ex 20:11]