Joshua - Chapter 5
A National Circumcision. (What, Again?)
When the kings of the Canaanite nations heard about the miracle that G-d performed for the Jews at the Jordan, they weren't too happy. In fact, they were petrified!
Meanwhile, Yehoshua set about circumcising all of the Jewish males. (They hadn't performed the mitzvah of bris milah - circumcision - during the forty years in the desert because they had to be ready to travel at a moment's notice and that could be dangerous for newborns who just had surgery.) Joshua 4:19 tells us that the nation crossed the Jordan on the 10th day of the month of Nisan. Having entered into the Land of Israel, the Jews would celebrate, in four days' time, the first Pesach since leaving Egypt. Since an uncircumcised male may not eat the korban Pesach (Passover sacrifice - see Exodus 12:48), a national circumcision was necessary for the second time. (The first was before the Exodus from Egypt.) After offering the korban Pesach, the manna which the Jews received daily in the wilderness ceased.
While Yehoshua was standing outside of Jericho, he was confronted by a malach (angel) with a drawn sword. The malach told Yehoshua symbolically that he had been neglecting his spiritual obligations and not to do so, as the conquest of the land would not - could not - be carried out by natural means alone. The Talmud (Megilla 3a) identifies the primary problem as bitul Torah - neglecting Torah study - a problem which Yehoshua immediately rectified.