Then Abraham took Ishmael his son and all of his house-born slaves and all his purchased slaves—every male among the men of Abraham’s house—and he circumcised the flesh of their foreskin on this very same day, just as God had spoken with him.
But if an outsider dwells with you, who would keep the Passover for Adonai, all his males must be circumcised. Then let him draw near and keep it. He will be like one who is native to the land. But no uncircumcised person may eat from it.
Circumcise yourselves to Adonai and remove the foreskins of your heart, men of Judah and inhabitants of Jerusalem. Else My wrath will break out like fire and blaze, with no one to quench it, because of your evil deeds!”
“Then God gave Abraham the covenant of circumcision. So he became the father of Isaac and circumcised him on the eighth day, and so Isaac with Jacob, and Jacob with the twelve patriarchs.
Therefore, keep in mind that once you—Gentiles in the flesh—were called “uncircumcision” by those called “circumcision” (which is performed on flesh by hand).
Also Adonai your God will circumcise your heart and the heart of your descendants—to love Adonai your God with all your heart and with all your soul, in order that you may live.
Now 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.