Augustine of Hippo

(Tr. xxx. 5) Circumcision also was perhaps a type of our Lord Himself. For what is circumcision but a robbing of the flesh, to signify the robbing the heart of its carnal lusts. And therefore it was not without reason that it was applied to that member by which the mortal creature is propagated: for by one man sin entered into the world. (Rom. 5:12) And therefore every one is born with the foreskin, because every one is born with the fault of his propagation. (vite propagenis) And God does not change us either from the corruption of our birth, or from that we have contracted ourselves by a bad life, except by Christ: and therefore they circumcised with knives of stone, to prefigure Christ, who is the stone; and on the eighth day, because our Lord’s resurrection took place on the day after the seventh day; which resurrection circumcises us, i. e. destroys our carnal appetites. Regard this, saith our Lord, as a type of My good work in making a man every whit whole on the sabbath day: for he was healed, that he might be whole in body, and he believed, that he might be whole in mind. Ye are forbidden indeed to do servile work on the sabbath; but is it a servile work to heal on the sabbath? Ye eat and drink on the sabbath, because it is necessary for your health: which shews that works of healing are by no means to be omitted on the sabbath.