John Calvin Commentary Numbers 14:21

"but in very deed, as I live, and as all the earth shall be filled with the glory of Jehovah;" — Numbers 14:21 (ASV)

But as truly as I live, all the earth. It is indeed plain that God here swears by His life and glory. The meaning is ambiguous only in this respect: some translate it in the past tense, that the earth had been filled with His glory, which had already been displayed in so many miracles. And this seems to accord well with what follows: Those who have seen my glory—shall not see the land; still, the future tense suits the context better, namely, that God would call His glory to witness, which He will assert in the future.

Moses feared that the destruction of the people would be turned into a reproach and contempt against God. God now declares with an oath that He would so vindicate His glory that those who were guilty of so great a crime should not escape punishment.

He proclaims that those should not see the land who had shut their eyes against the miracles, of which they had been spectators and eyewitnesses, and in their blindness had endeavored to disregard them. For, since they had not been taught to fear God by so many signs, they were worse than unworthy of seeing the land, the possession of which ought to have been assured to them by those very signs, if God’s truth had not been utterly rejected by their ingratitude.

God complains that He had been tempted by them ten times, because they had not ceased constantly to provoke Him by their stubbornness. For this is no fixed or definite number that is intended; rather, God merely indicated that they had done so without measure or end. We have elsewhere⁶⁰ shown what it is to tempt God, namely, to subject His power to the narrow rule of our own senses and to prescribe to Him the way He is to act according to our own desires, so that we submit to Him only as far as our carnal reason dictates. The source and cause of this tempting of God is then explained: that is, when men refuse to listen to His voice, since nothing but obedience, which is the mistress of humility, can restrain our insolence.

⁶⁰ See ante, vol. 1, p. 421, on , on Deuteronomy 6:16..