After each day of creation, God sees that His work is “good.” After the first six days are through, God sees that His work is “very good.”
The word “very” is used to mark the end of the creation cycle, since God had finished creating the realms and the rulers.
God “rested” on the 7th day.
It’s not that God got tired; we should see this rest and blessing as the first of the cycle of covenants that we will see throughout the Bible.
God, by His act of establishing the Sabbath, is making a covenant with His creation, and especially with all of humanity, represented by the man He created in His own image. That seems to be what Jesus is getting at when He says: “The Sabbath was made for man, not man for the Sabbath” (Mark 2:27-28).
Also, the Hebrew word for “oath-swearing” is sheba, a word that’s based on the Hebrew word for the number “seven.” In Hebrew, to swear an oath, which is what you do when you make a covenant, is “to seven oneself” (see Abraham’s oath in Genesis 21:27-32).
So, what God seems to be doing here on the seventh day, is not resting, but binding Himself to His creation in a perpetual covenant relationship. And we’ll see this pattern of covenant continuing throughout the Bible.