But circumcision, they knew, was a required thing and perhaps they forgot it a little bit during the enslavement in Egypt. God reminded Moses very forcibly in Exodus 4:24-26 that he needed to circumcise his son and so Zipporah did that for him, much to her consternation. Then the Passover requirements that are given in Exodus 12 explicitly forbids any uncircumcised person to partake of it. So they must have undergone a forced, if you will, circumcision of all adult males at that time, right around Passover before they left Egypt. It was performed again as they entered the Promised Land under Joshua, in Joshua 5. So we have these instances in the Pentateuch of circumcision being done.
