John Calvin Commentary Numbers 14:39

"And Moses told these words unto all the children of Israel: and the people mourned greatly." — Numbers 14:39 (ASV)

And Moses told all these sayings. It was, indeed, a just cause for mourning when they heard that God, whose patient endurance they had so recklessly abused, would from now on be unyielding. Yet here we have set before our eyes that sorrow of the world which worketh death, as Paul says (2 Corinthians 7:10), when the wicked, as they weep and complain, continue to murmur against God; even when they gnaw the bit with greater obstinacy and thus, like savage and untamable beasts, rush forward to their destruction in blind desperation.

The temporal punishment could not, indeed, be redeemed by any tears; but, if there had been the willingness to repent, their only remedy would have been to voluntarily submit themselves and calmly undergo whatever discipline God might be pleased to inflict. First of all, however, they proudly struggle to shake off the punishment awarded to them, and while they pretended penitence, increasingly kick against God.

There is no doubt that it was under the pretense of submission that they prepared themselves the next day to advance; but why was this, except to overturn God’s inviolable decree? Nevertheless, they sought, as if against His will, to make a way for themselves, though He forbade.

“Behold us,” they said, “we are ready;” but it was too late, for the opportunity had fled. For, as the Prophet exhorts us to seek the Lord while he may be found (Isaiah 4:6), so also we should follow Him when He calls us.

But what good was this untimely eagerness of the people? When God wished them to retire into the desert, they pretended to desire to obey Him by advancing further, and still wished for their confession of sin to be accepted as a sufficient satisfaction.