And in the eighth day the flesh of his foreskin shall be circumcised.
Read Chapter 12
Augustine of Hippo
It was certainly not for nothing that the commandment was given for the child “to be circumcised on the eighth day”; it can only have been because the rock, the stone with which we are circumcised, was Christ. It was “with knives of rock” or stone that the people were circumcised;“now the rock was Christ.” So why on the eighth day? Because in sevenday weeks the first is the same as the eighth; once you’ve completed the seven days, you are back at the first. The seventh is finished, the Lord is buried; we are back at the first, the Lord is raised up. The Lord’s resurrection, you see, promised us an eternal day and consecrated for us the Lord’s day. It’s called the Lord’s because it properly belongs to the Lord, because on it the Lord rose again. The rock has been restored to us; let those be circumcised who wish to say, “For we are the circumcision.”