Joshua 5:8

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.

Robert Jamieson, A. R. Fausset & David Brown, 1871 · public domain

Verse 8 They abode - in the camp, till they were whole - This required several days; see the notes on Gen 34:24, Gen 34:25. Sir J. Chardin informs us that when adults were circumcised they were obliged to keep their beds for about three weeks, or at least during that time they are not able to walk about but with great difficulty. The account he had from several renegadoes, who had received circumcision among the Mohammedans. Is it not strange that during this time they were not attacked by the inhabitants of the land, and utterly destroyed, which might have been easily effected? See the case of the poor Shechemites, as related in Gen 34:24-31, with the notes there. Joshua, as an able general, would at once perceive that this very measure must expose his whole host to the danger of being totally annihilated; but he knew that God could not err, and that it was his duty to obey; therefore in the very teeth of his enemies he reduced the major part of his army to a state of total helplessness, simply trusting for protection in the arm of Jehovah! The sequel shows that his confidence was not misplaced; during the whole time God did not permit any of their enemies to disturb them. The path of duty is the path of safety; and it is impossible for any soul to be injured while walking in the path of obedience. But why did not God order them to be circumcised while they were on the east side of Jordan in a state of great security? Because he chose to bring them into straits and difficulties where no counsel or might but his own could infallibly direct and save them; and this he did that they might see that the excellence of the power was of God, and not of man. For the same reason he caused them to pass the Jordan at the time that it overflowed its banks, and not at the time when it was low and easily fordable, that he might have the better opportunity to show them that they were under his immediate care and protection; and convince them of his almighty power, that they might trust in him for ever, and not fear the force of any adversaries. In both cases how apparent are the wisdom, power, and goodness of God!

Adam Clarke, 1831 · public domain