John Calvin Commentary Hebrews 4:8

"For if Joshua had given them rest, he would not have spoken afterward of another day." — Hebrews 4:8 (ASV)

For if Jesus had given them rest, or, had obtained rest for them, etc. The Apostle did not mean to deny that David understood rest as the land of Canaan, into which Joshua led the people. However, he denies that this is the final rest to which the faithful aspire, and which we also have in common with the faithful of that age.

For it is certain that they looked higher than that land. Indeed, the land of Canaan was valued so much primarily because it was an image and a symbol of the spiritual inheritance.

Therefore, when they obtained possession of it, they should not have rested as though they had attained the summit of their desires. On the contrary, they should have meditated on what was spiritual, as suggested by it. Those to whom David addressed the Psalm were in possession of that land, but they were reminded of the duty of seeking a better rest.

We then see in what way the land of Canaan was a rest: it was indeed evanescent, beyond which it was the duty of the faithful to advance. In this sense, the Apostle denies that Joshua gave that rest, for the people under his guidance entered the promised land for this purpose: that they might with greater eagerness advance towards heaven.

And from this we may easily learn the difference between us and them. For though the same purpose is intended for both, they had external types added to guide them. We do not have such types, nor do we indeed need them, for the naked truth itself is set before our eyes.

Though our salvation is still in hope, yet the truth itself leads directly to heaven. Nor does Christ extend His hand to us to lead us by the indirect course of types and figures, but rather to withdraw us from the world and raise us to heaven.

The Apostle separates the shadow from the substance for this reason: because he was dealing with the Jews, who were too much attached to external things.

He draws the conclusion that there is a 'sabbath-keeping' reserved for God's people, that is, a spiritual rest, to which God daily invites us.