The seventh day and God's rest
Hebrews quotes Genesis's account of God resting on the seventh day while urging believers to enter the rest God still promises.
For somewhere He has spoken about the seventh day in this manner: “And on the seventh day God rested from all His works.” And again, as He says in the passage above: “They shall never enter My rest.”
There remains, then, a Sabbath rest for the people of God. For whoever enters God’s rest also rests from his own work, just as God did from His. Let us, therefore, make every effort to enter that rest, so that no one will fall by following the same pattern of disobedience.
Genesis 2:2-3 says that God rested from His work on the seventh day and blessed that day; Hebrews 4:4 quotes the seventh-day statement while explaining that a Sabbath rest remains for God's people.