John Calvin Commentary Deuteronomy 1:41

"Then ye answered and said unto me, We have sinned against Jehovah, we will go up and fight, according to all that Jehovah our God commanded us. And ye girded on every man his weapons of war, and were forward to go up into the hill-country." — Deuteronomy 1:41 (ASV)

Then you answered and said to me. The repentance was too late, which drove the Israelites to their untimely effort of activity. Although, as I have explained above, they did not truly and seriously repent, since, when they should have patiently endured God's discipline, they tried to shake it off and drive it far away from them by a new act of disobedience. In short, they did nothing else but kick against the pricks.

But such is the wilfulness of people, when their own fancy leads them, that they will dare anything God forbids. In this, however, their far worse folly revealed itself: when they were again held back, they still refused to obey. Besides, He did not merely forbid them to fight, but also denied them His assistance.

What then could be more monstrous? In opposition to God’s will, and after the hope of His assistance was withdrawn, they engaged in what they had just before obstinately refused to attempt under His guidance, by His command, and with the sure promise of success. And yet, hypocrisy so blinds people’s minds that they imagined they were correcting and compensating for the evil they had doubled.

Moses then relates how they received the reward they deserved; it was as if to say that, although they might be slow to learn, they were still made aware, by the setback they experienced, how fatal it is not to obey God: for fools never learn wisdom except under the rod.