Genesis 2:3
Then God blessed the seventh day and sanctified it, because on that day He rested from all the work of creation that He had accomplished.
What it says
God blesses the seventh day and makes it holy because on it he rests from all his creating work. The day is marked out by God's own action.
What it is doing
This verse gives the theological weight of the seventh day within the chapter.
In context
1Thus the heavens and the earth were completed in all their vast array. 2And by the seventh day God had finished the work He had been doing; so on that day He rested from all His work. 3Then God blessed the seventh day and sanctified it, because on that day He rested from all the work of creation that He had accomplished.