What does Hebrews 4:7 mean?

In chapter 3, the writer of Hebrews warned his fellow Christians not to doubt the promises of God. He gave the example of Israel's failure in the desert, at the border of the Promised Land (Numbers 13—14). By quoting Psalm 95, the writer explained that God's promise of rest—a separate issue from our eternal salvation—is dependent on whether we "hold fast" to our faith (Hebrews 3:6). Those Israelites who failed to fulfill the work given to them by God were denied their "rest" of the Promised Land.

This passage, completed in verse 10, points out that the inheritance "rest" offered by God is still available to those willing to trust and obey. Certain false teachers of this era claimed that Christ had already returned in His second coming, forcing teachers like Paul to counter their errors (2 Thessalonians 2:1–3; 2 Timothy 2:17–18). In particular, the writer of Hebrews points out that Psalm 95 uses the word "today," even though the Psalm was written long after Moses' time. In other words, the Scripture is saying, "this means you" to those who read it.

Since God's seventh-day Sabbath rest is still ongoing (Hebrews 4:9), and Joshua's victory in Canaan was not a complete fulfillment of the promises of God (Hebrews 4:8), and since disobedience was what kept Israel out of the Promised Land, there is still a "rest" inheritance available for those who faithfully complete the works assigned to them by God (Hebrews 4:10). This, in fact, is the meaning of the term "rest" as used here: a completion of our works resulting in victory.