Hebrews 4:6-11
6 Therefore since it still remains for some to enter that rest, and since those who formerly had the good news proclaimed to them did not go in because of their disobedience, 7 God again set a certain day, calling it “Today.” This he did when a long time later he spoke through David, as in the passage already quoted:
8 For if Joshua had given them rest, God would not have spoken later about another day. 9 There remains, then, a Sabbath-rest for the people of God; 10 for anyone who enters God’s rest also rests from their works,[e] just as God did from his.11 Let us, therefore, make every effort to enter that rest, so that no one will perish by following their example of disobedience.
It is about entering God's rest and the Sabbath day. In the proceeding verses the author of Hebrews outlines that God created the Sabbath and because of some of the Israelite's disobedience the were not permitted to enter in to God's rest, but that has been changed, God has opened up the way to His rest and has declared that it is Today.
Maybe this is trying to remind us that if we will let God speak to us and are willing to hear his voice we don't have to caught up in the overwhelming busyness of life. We will not be saved by what we do, but rather we can rest because God has shown us grace.
To go a little further, maybe because we are God's people we have the privilege of participating in God's rest everyday. We are reminded that it is by grace that we are saved and we don't have to continue to strive for what we cannot attain.
