Charles Ellicott Commentary Joshua 5:4

"And this is the cause why Joshua did circumcise: all the people that came forth out of Egypt, that were males, even all the men of war, died in the wilderness by the way, after they came forth out of Egypt." — Joshua 5:4 (ASV)

The reason Joshua circumcised. —As the narrative stands, it is not entirely obvious why uncircumcision is called “the reproach of Egypt,” whereas all the people born in Egypt were circumcised. The uncircumcision pertained to those who were born in the wilderness during the years of wandering. But that period of wandering, between the departure from Kadesh-barnea and the return to Kadesh (thirty-seven and a half years, Numbers 15–19, inclusive), is a kind of blank in the story of the Exodus.

The five chapters which belong to it in the Book of Numbers contain no note of progress as to time or place. The people had turned back in their hearts to Egypt (Acts 7:39; Numbers 14:4), and were bearing the reproach of their apostasy all those years, “the reproach of Egypt.” Suffering under the breach of promise of Jehovah (Numbers 14:34), they appear to have omitted the sign of the covenant, as though they were no longer the people of God. The passage of the Jordan was the practical proof of Israel’s restoration to Divine favour, and they were brought into covenant with Him once more.