וְזֶ֥ה הַדָּבָ֖ר אֲשֶׁר־מָ֣ל יְהוֹשֻׁ֑עַ כָּל־הָעָ֣ם הַיֹּצֵא֩ מִמִּצְרַ֨יִם הַזְּכָרִ֜ים כֹּ֣ל ׀ אַנְשֵׁ֣י הַמִּלְחָמָ֗ה מֵ֤תוּ בַמִּדְבָּר֙ בַּדֶּ֔רֶךְ בְּצֵאתָ֖ם מִמִּצְרָֽיִם׃
И это причина, по которой Иисус сделал обрезание: все люди, которые вышли из Египта, которые были мужчинами, даже все люди войны, кстати, умерли в пустыне после того, как они вышли из Египта.
Rashi
And this is the reason. [Lit. and this is the thing] After this speech he circumcised them. He said to them. “Do you think you will inherit this land while you are yet uncircumcised? Was it not said to Avrohom, ‘And you will preserve My covenant etc.’ ‘and I will give you and your descendants after you, the land of your sojournings.’”4Bereishis 17:8,9. Thus the inheritance of the land was dependent on their preserving the covenant, which was the rite of circumcision.
Rashi
All the people that went out. Not one of them was here for they had all died, and they had all been circumcised, as it is said, ‘for they were circumcised.’5Next verse.
Tze'enah Ure'enah
“This is the reason why Joshua had the circumcision performed” [5:4]. For this reason, Joshua circumcised the Israelites because the children that were born in the desert had not been circumcised in the desert. Therefore, they now had to be circumcised. Another reason was that he admonished Israel that they circumcise themselves so that they should know that they would not come into the Holy Land. You must circumcise yourselves since the Holy Land, the land of Israel, belongs to the Holy One. That is to say, the Holy One is the king of the land of Israel. Other lands have kings placed over them. That is why whoever pursues illicit sex in the land of Israel, the land spits them out and throws them out. However, in other lands that have kings over them, if they pursue illicit sex, the land is not so holy. Therefore, they remain in their land. That is why Joshua said to Israel, you are coming into a holy land. Therefore, circumcise yourselves in the hope that you will not come to illicit sexual relations.