8. when they had done circumcising all the people--As the number of those born in the wilderness and uncircumcised must have been immense, a difficulty is apt to be felt how the rite could have been performed on such a multitude in so short a time. But it has been calculated that the proportion between those already circumcised (under twenty when the doom was pronounced) and those to be circumcised, was one to four, and consequently the whole ceremony could easily have been performed in a day. Circumcision being the sign and seal of the covenant, its performance was virtually an investment in the promised land, and its being delayed till their actual entrance into the country was a wise and gracious act on the part of God, who postponed this trying duty till the hearts of the people, animated by the recent astonishing miracle, were prepared to obey the divine will.
      they abode in their places . . . till they were whole--It is calculated that, of those who did not need to be circumcised, more than fifty thousand were left to defend the camp if an attack had been then made upon it.

JFB.