That the new generation was to be circumcised testifies to God’s faithfulness; he has not given up on his promises. Even though almost an entire generation of Israelites had given up on God and neglected his promises (Joshua 5:3–6), the Lord remains faithful. The promises made to Abraham will be kept. One generation might die in the desert, but God has the power to raise up a new generation and mark them out as his own.
Circumcision also served to indicated that the reproach of Egypt has been removed (Joshua 5:9). The circumcision of the new generation in the land of Canaan is a practical declaration of the perfect restoration of the covenant. Bearing the mark of the covenant of grace, the people have a sure pledge that the Lord will give them the land of Canaan for their inheritance. There will be no more wandering. The time of fulfillment has come. The Lord is faithful to his promises.
4 And this is the reason why Joshua circumcised them: all the males of the people who came out of Egypt, all the men of war, had died in the wilderness on the way after they had come out of Egypt.