In our text, the Hebrew writer enlarges upon his statement in 3:19 that the Israelites were not able to enter into the rest of God (the land of Canaan) because of their unbelief.
He begins by noting that a promise of rest remains for God’s people. The reference here is obviously to heaven, the final rest promised to the people of God. He refers to several “rests” in the text. The rest of God after the creation of the world, “And on the seventh day God ended His work which He had done, and rested…” (Genesis 2:2). The rest of Canaan missed by the unbelieving Jews, “They shall not enter My rest” (5). He then refers to Psalm 95 where David mentions those rebellious Jews, and said, “Today, if you will hear His voice: Do not harden your hearts, as in the wilderness…” (7-8). In the word “Today”, David was indicating another rest yet attainable for the people of God.
The key is the same here. We must believe to attain the eternal rest promised by God. “For he who has entered His rest has himself also ceased from his words as God did from His” (10). Do not harden your heart. Believe in the promise of God!
