‘ And their children whom he raised up in their stead, them Joshua circumcised, for they were circumcised, because they had not circumcised them by the way.'
Here it is specifically stated that those who were now to be circumcised were those born ‘by the way' i.e. on the journey, those who replaced the condemned generation and had not been circumcised.
These rather complicated verses were trying to explain briefly, to those who assumed circumcision as practised on the eighth day after birth, the reason why a circumcision ceremony was necessary,. They were trying to present succintly a very complicated situation. We must not overpress the detail.