‘ And this is the reason why Joshua circumcised. All the people who came out of Egypt who were males, even all the men of war, died in the wilderness by the way, after they came out of Egypt. For all the people who came out were circumcised. But all the people who were born in the wilderness by the way, as they came out of Egypt, they had not been circumcised.'
The first ‘all the people' is a generalisation. Joshua and Caleb at least were present. The point is rather to explain why so many were uncircumcised.
All the circumcised males of twenty years old and upwards sentenced by YHWH to die, had died during the forty years, but many of those under twenty who would also have been circumcised would still be alive. However, those born in the wilderness journeying had not been circumcised. It need not specifically mean that no one was circumcised after the leaving of Egypt, only that it was not the general practise. This lack of circumcision would also be true of the children of the mixed multitude (Exodus 12:38), many of whom would not have been circumcised even in Egypt (although circumcision may have been required of them when they joined the covenant community). Thus those present with Joshua included many older men who had been circumcised and possibly some older men and certainly a large number of younger men and boys who had not. These were the ones to be circumcised as the covenant was renewed on entering the land.
The reason for not circumcising their infants may well have been because of the discomfort it would cause for everyone when they were journeying day by day. They would have been continually accompanied by infants in pain and discomfort who were being subjected to the extreme rigours of the journey. The fact that it had to take place on the eighth day (Leviticus 12:3) meant that it could not be left for a more convenient time.
“By the way, as they came out of Egypt.” Compare Deuteronomy 24:9; Deuteronomy 25:17. Once again we have evidence how well Joshua knew the words of Moses.