Joshua 5:4

4 And this [is] the thing [for] which Joshua circumciseth [them]: all the people who are coming out of Egypt, who are males, all the men of war have died in the wilderness, in the way, in their coming out of Egypt,

Joshua 5:4 Meaning and Commentary

Joshua 5:4

And this [is] the cause why Joshua did circumcise
Or the reason of the command given him to circumcise the children of Israel at this time, namely, what follows:

all the people that came out of Egypt [that were] males, [even] all
the men of war;
meaning such that were twenty years old, and upwards:

died in the wilderness, by the way, after they came out of Egypt;
not directly, but in a course of forty years, as they journeyed through the wilderness; this is to be understood with an exception of Joshua, Caleb, Eleazar but then there was a large number who were under twenty years of age, that came out of Egypt, and were now living.

Joshua 5:4 In-Context

2 At that time said Jehovah unto Joshua, `Make for thee knives of flint, and turn back, circumcise the sons of Israel a second time;'
3 and Joshua maketh for him knives of flint, and circumciseth the sons of Israel at the height of the foreskins.
4 And this [is] the thing [for] which Joshua circumciseth [them]: all the people who are coming out of Egypt, who are males, all the men of war have died in the wilderness, in the way, in their coming out of Egypt,
5 for all the people who are coming out were circumcised, and all the people who [are] born in the wilderness, in the way, in their coming out from Egypt, they have not circumcised;
6 for forty years have the sons of Israel gone in the wilderness, till all the nation of the men of war who are coming out of Egypt, who hearkened not to the voice of Jehovah, to whom Jehovah hath sworn not to show them the land which Jehovah sware to their fathers to give to us, a land flowing with milk and honey, are consumed;
Young's Literal Translation is in the public domain.