Joshua 5:2-5

2At that time Adonai said to Joshua, “Make yourself flint knives and circumcise again Bnei-Yisrael a second time.”

3So Joshua made flint knives and circumcised Bnei-Yisrael at Gibeath-ha-araloth.

4Now this is the reason why Joshua circumcised: all the people that came out of Egypt who were males—all the men of war—had died in the wilderness along the way after they came out of Egypt.

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