Joshua 5:2-5

2At that time the Lord said to Joshua, “Make flint knives and circumcise the Israelite men again.”

3So Joshua made flint knives and circumcised the Israelite men at Gibeath-haaraloth.

4This is the reason Joshua circumcised them: All the people who came out of Egypt who were males — all the men of war — had died in the wilderness along the way after they had come out of Egypt.

5Though all the people who came out were circumcised, none of the people born in the wilderness along the way were circumcised after they had come out of Egypt.