It's right there. It is clearly talking about how the promise land was not the rest that remains still to be had. We will get it in the consummation.
8For if Joshua had given them rest, God would not have spoken of another time later on. 9Consequently,s there remains a Sabbath celebration for the people of God. 10For whoever enters God’s rest has also rested from his own work, as God did from his. 11Let us, therefore, make every effort to enter that rest; otherwise, one of you might perish through the same example of disobedience.
In v 9 the writer repeats the conclusion of v 6a, but the term σαββατισμός is substituted for the characteristic term κατάπαυσις. The formal parallelism suggests that the substitution is meant to define more precisely the character of the future rest promised to the people of God (Hofius, Katapausis, 106). If it had been the writer’s intention to say only “there remains a Sabbath rest for the people of God” (cf. RSV, NEB, NIV), he could have retained the word κατάπαυσις. In v 4 he had associated κατάπαυσις with God’s rest on the seventh day, and he undoubtedly knew that the word was used for the Sabbath rest in the LXX (Exod 35:2; 2 Macc 15:1). The deliberate choice of σαββατισμός, which finds its earliest occurrence in extant Greek literature here, must have been dictated by the fact that it conveyed a nuance not found in κατάπαυσις.
The term σαββατισμός appears to have been coined from the cognate verb σαββατίζειν, “to observe/to celebrate the Sabbath.” In its only occurrence in non-Christian literature (Plutarch, Concerning Superstition 3 [Moralia 166 A]), the term signifies Sabbath observance. In four other documents from the patristic period that are independent of Heb 4:9, the term denotes the celebration or festivity of the Sabbath (Justin, Dialogue with Trypho 23.3; Epiphanius, Against All Heresies 30.2.2; The Martyrdom of Peter and Paul, chap. 1; ApostConst 2.36.2; discussed by Hofius, Katapausis, 103–6). The term received its particular nuance from the Sabbath instruction that developed in Judaism on the basis of Exod 20:8–10, where it was emphasized that rest and praise belong together (cf. 2 Macc 8:27; Jub. 50:8; Ps-Philo, Bib. Ant. 11.8). The term σαββατισμός stresses the special aspect of festivity and joy, expressed in the adoration and praise of God (cf. Hofius, Katapausis, 106–10; Losada, RevistB 36 [1974] 127). In v 9 this nuance defines the character of the promised rest awaiting the people of God in the consummation.The assertion in v 10 stands in a causal relationship to v 9 and clarifies why in the eschatologial rest a σαββατισμός will be possible.
Whoever has entered the consummation-rest will experience the completion of his work, as did God after the creation (vv 3c–4), and will enjoy the rest that is necessary for the festivity and praise of a Sabbath celebration. In conjunction, vv 9–10 anticipate the festival of the priestly people of God in the heavenly sanctuary, celebrating in the presence of God the eternal Sabbath with unceasing praise and adoration
Lane, William L.. Hebrews 1-8, Volume 47A (Word Biblical Commentary) (p. 102). Zondervan Academic
