(John7:22 KJV) Moses therefore gave unto you circumcision; (not because it is of Moses, but of the fathers;) and ye on the sabbath day circumcise a man.
(John7:23 KJV) If a man on the sabbath day receive circumcision, that the law of Moses should not be broken; are ye angry at me, because I have made a man every whit whole on the sabbath day?
God also refers to circumcision as a perpetual covenant in Genesis 17:11-13, to incense as one in Exod 30:8, to the Levitical priesthood as one in Exod 29:9. All these so-called perpetual covenants have been done away with at the cross. Just because they are called perpetual covenants does not mean that their purpose will never come to an end. Circumcision was for ALL Abraham’s generations, yet although we are part of that people, circumcision if not necessary for Christians. The same goes for the Sabbath.
The Sabbath was made for man, and so was circumcision. They served their purpose, and Acts 15 tells us we need not circumcise any longer, and Col 2:16 and other texts tell us the same about the Sabbath.