(50) Why does he order all slaves to be circumcised, those born in the family and also those who are bought? (#Ge 17:12). The literal meaning is plain; for it is fitting that servants should imitate their masters on account of their necessary employment, and the services to which they are bound in life. But with respect to the inner object of the command, those dispositions are what may be called born in the family which are influenced by nature itself, and those are bought which can be changed for the better by teaching and instruction. Each of these has its appropriate employment, and requires like a plant to be cleared and pruned in order that the good and fruitful parts may acquire constancy; for fertile plants produce many superfluous things by reason of their fecundity, and those superfluities must be cut away; but those who are taught by instructors cut away their ignorance.
(51) What is the meaning of, “And it shall be my covenant (or agreement) in your flesh?” (Genesis 17:13). God is willing to do good, not only to the man who is endued with virtue, but he wishes that the divine word should regulate not only his soul but his body also, as if it had become its physician. And it must be its care to prune away all excesses of seeing, and hearing, and taste, and smell, and touch, and also those of the instrument of voice and articulation, and also all the redundant and pernicious impulses of the genitals, as also of the whole body, the effect of which is, that at times we are delighted by our passions and at times pained by them.
(52) Why is it that he pronounces a sentence of death on an infant, saying, “Every male child who is not circumcised, who has not been circumcised (or, as the Greek has it, who shall not be circumcised) in the flesh of his foreskin on the eighth day, that soul shall be cut off from his generation?” (#Ge 17:14). The law never declares a man guilty for any unintentional offence; since even those who have committed an unintentional homicide are pardoned by it, cities being set apart into which such men may flee and there find security; for whoever escapes to them is rendered secure and free from danger; and no one has the power to drag him forth, or to cite him before the tribunal of the judge for the deed. Therefore, if a boy is not circumcised on the eighth day after his birth, what offence will he have committed that he is to be held guilty, and suffer the penalty of death? Some persons may perhaps say that the form of the command points to the parents themselves, for they look upon them as despisers of the command of the law. But others say that it has here exerted excessive severity against infants, as it seems, imposing this heavy penalty in order that grown up persons who break the law may thus be irrevocably subjected to most severe punishment. This is the literal effect of the words. But if we look to their inward meaning, then what is male in us is most especially the intellect, and that God here commands to be circumcised on the eighth day, for the reason previously stated, not in any other part, but in the flesh of the foreskin, by this expression symbolically indicating those parts which in the flesh do subsequently become the organs of pleasure and impulse. And on this account it is that he introduces a legitimate reason, warning men that the intellect, which is not circumcised and cleared away from the flesh and the vices of the flesh, is corrupt and cannot be saved. But that this language is not to be applied to the man, but to the intellect, which is thus put in a sound condition, he tells us in the subsequent words, saying, “that soul shall be cut off,” not that human body, or that man, but that soul and mind. Cut off from what? From its generation; for the whole generation is incorrupt. Therefore the wicked man is removed from incorruption to corruption.