John Calvin Commentary Hebrews 3:11

"As I sware in my wrath, They shall not enter into my rest." — Hebrews 3:11 (ASV)

So I sware, etc. It was the punishment of their madness that they were deprived of the rest promised them. Moreover, the Lord calls the land where they could have had their dwelling, his rest. For they had been sojourners in Egypt and wanderers in the wilderness, but the land of Canaan was to be, according to the promise, their perpetual inheritance. It was in reference to this promise that God called it his rest, for we can have a settled dwelling nowhere except where we are fixed by his hand. But their right to a secure possession was founded on what God said to Abraham:

“To thy seed will I give this land” (Genesis 12:7).

By God swearing, If they shall enter, etc., the atrocity of their evil conduct is made more evident and is more powerfully shown, for it is an evidence of greatly inflamed wrath. “If they shall enter,” is in the form of an oath, in which something is to be understood, such as an imprecation or something similar, when humans speak. But when God speaks, it is as though he said, “Let me not be deemed true,” or, “Let me not be believed in the future, if this does not happen.” However, this elliptical mode of speaking counsels us to fear and reverence, so that we do not rashly swear, as many do who are often in the habit of pouring forth dreadful curses.

Regarding the present passage, we should not think that they were denied entrance into the land by God’s oath for the first time then, when they tempted him in Rephidim. For they had been excluded long before, from the time they refused to march forward at the report of the spies.

God, then, does not here attribute their expulsion from the land to this instance of tempting him as the primary cause. Rather, he intimates that no chastisement could have restored them to a sound mind; instead, they continually added new offenses. And so he shows that they fully deserved to be punished so severely, for they never ceased to increase his wrath more and more by various sins, as though he had said, “This is the generation to which I denied possession of the promised land, for during the entire forty years afterwards it revealed its obstinate madness by innumerable sins.”