In His abhorring of the people of Israel, God wanted to strike them with a pestilence and make of Moses a nation greater than they (Num. 14:11-12).
Moses prayed for them according to God's word, namely that Jehovah is slow to anger and abounding in mercy, forgiving iniquity and transgression (vv. 13-19). Moses was a God-man; he knew God. Therefore, he did not pray according to his concept; rather, he prayed according to God's concept, according to what God is, what God speaks, and what God promises. Moses did not argue with God, but he did pray to God. His prayer, saying that Jehovah is slow to anger and abounding in mercy, forgiving iniquity and transgression, bound God according to what He had spoken and what He is.
God forgave the people according to Moses' prayer (v. 20), but their unbelief nevertheless had certain negative consequences (vv. 21-38).
God would not allow those who murmured against Him to see and enter into the good land. Rather, with the exception of Caleb and Joshua, their carcasses would fall in the wilderness (vv. 22-30, 32).
The people had said that their little ones would become a prey and would be taken over by the Canaanites and the Nephilim. But God said, "Your little ones, who you said would become a prey, I will bring in, and they shall know the land which you have rejected" (v. 31).
The rebellious ones and their children would be wanderers in the wilderness forty years to bear their iniquities according to the number of days (for every day a year) in which they spied out the land (vv. 33-34).
The men who returned with an evil report and made all the assembly murmur against Moses died by the plague before Jehovah (vv. 36-38). Even though all the people rebelled against Him, God did not destroy the entire people. Instead, God killed the ten men who instigated the rebellion.