Mishneh Torah (Rambam) משנה תורה

Circumcision is a positive mitzvah [whose lack of fulfillment] is punishable by karet, as [Genesis 17:14] states: "And an uncircumcised male who does not circumcise his foreskin - this soul will be cut off from his people." A father is commanded to circumcise his son, and a master, his slaves. This applies both to those who are born in his home and to those purchased by him. If the father or the master transgressed and did not circumcise them, he negated the fulfillment of a positive commandment. He is not, however, punished by karet, for karet is incurred only by the uncircumcised person himself. The court is obligated to circumcise that son or slave at the proper time and should not leave an uncircumcised male among the Jewish people or their slaves.

We may not circumcise a person's son without his knowledge, unless he has transgressed and did not circumcise him. [In such an instance,] the court must circumcise [the child] against [the father's] will. If the matter does not become known to the court and they do not circumcise him, when [the child] reaches bar mitzvah, he is obligated to circumcise himself. With each and every day that passes after he has reached bar mitzvah, he negates a positive commandment. He is not, however, liable for karet until he dies uncircumcised, having intentionally [failed to perform the mitzvah].

A master is obligated to circumcise both a slave who was born as the property of a Jewish owner and a slave purchased from the gentiles. [There is, however, a difference between the two.] A home-born slave should be circumcised on the eighth day [of his life]. In contrast, a slave who is purchased should be circumcised on the day he was purchased. If he was purchased on the day he was born, he should be circumcised on that day.

There are, however, slaves that are purchased who should be circumcised on the eighth day [of their lives], and home-born slaves who should be circumcised on the day they are born. What is implied? Should one purchase a maidservant and purchase [the rights to] her fetus [separately], when she gives birth, the baby should be circumcised on the eighth day. Although the fetus itself was purchased separately, since [the master] purchased his mother before the child was born, he should be circumcised on his eighth day.

If a person purchased a maidservant for her offspring, or purchased a maidservant with the intent of not immersing her as a slave, even though her offspring is born in his domain, the child should be circumcised on the day he was born. [This ruling was granted, because] this child is considered as if he alone has been purchased [by his master], and it is as if he purchased him this day. His mother is not included among the maidservants of the Jewish people, so that the child could be considered "home-born." If his mother immersed herself after she gave birth, the child should be circumcised on the eighth day.

When a person purchases a slave from the gentiles and the slave does not consent to be circumcised, we may be patient with him for twelve months. It is forbidden to maintain him for any longer period while he remains uncircumcised, and one must sell him to gentiles. If, at the outset, while the slave was still in the possession of his gentile master, he made a stipulation that he would not be circumcised, it is permissible to maintain him although he is not circumcised, provided he accepts the seven universal laws commanded to the descendants of Noah and becomes a resident alien. If he refuses to accept these seven laws, he should be killed immediately. A resident alien may be accepted only in the era when the laws of yovel are in effect.

When a convert enters the congregation of Israel, he is obligated to undergo circumcision first. If he had been circumcised while he was a gentile, it is necessary to extract the blood of the covenant on the day that he converts. Similarly, a child who was born without a foreskin must have blood extracted for circumcision on the eighth day. An androgynous, a child with both male and female sexual organs, must be circumcised on the eighth day. Similarly, a child born by Caesarian section and a child who has two foreskins should both be circumcised on the eighth day.

Circumcision is performed only during the day, after the rising of the sun, as [Leviticus 12:3] states, "On the eighth day...," i.e., during the day, and not at night. [This applies to a circumcision performed] at the appropriate time, the eighth day [after birth], and [to a circumcision performed] after the appropriate time, from the ninth day and onward. If one performed the circumcision after dawn, it is acceptable. It is acceptable [at any time] throughout the entire day. Nevertheless, it is a mitzvah to [perform the circumcision] early, in the beginning of the day, since "the eager perform mitzvot early."

When a circumcision [is performed] at its appropriate time, [its performance] supersedes [the prohibition against labor] on the Sabbath. When it [is] not [performed] at its appropriate time, [its performance] does not supersede [the prohibition against labor] on the Sabbath or the festivals. Whether or not it is performed at its appropriate time, [its performance] supersedes [the prohibition against removing signs of] tzara'at. What is implied? If there was a sign of tzara'at on the foreskin, it may be cut off with the foreskin. Although there is a prohibition against cutting off the signs of tzara'at, the performance of a positive commandment supersedes the observance of a negative commandment.

Just as the circumcision of sons supersedes [the prohibitions against labor on] the Sabbath, so too, the circumcision of those slaves who are circumcised on the eighth day [of their lives] supersedes [the prohibitions against labor on] the Sabbath when the eighth day [of their life] falls on the Sabbath. There is [one] exception - a slave whose mother did not immerse herself until after she gave birth. Although such a slave is circumcised on the eighth day, his circumcision does not supersede [the prohibitions against labor on] the Sabbath.

[The circumcision of the following individuals] does not supersede [the prohibitions against labor on] the Sabbath: a child who was born without a foreskin; a child who was born in the eighth month of pregnancy before his development was completed; he is considered to be a stillborn, for he will not live; a child born by Caesarian section; an androgynous; and a person with two foreskins. These individuals are circumcised on [the following] Sunday, the ninth day of their lives.

When a child is born beyn hash'mashot, which is a period when it is undetermined whether it is considered day or night, we count from the night, and he is circumcised on the ninth day [following the day he was born], which could be the eighth day. When a child is born beyn hash'mashot on Friday, his circumcision does not supersede the Sabbath prohibitions, because the Sabbath prohibitions are never superseded because of a doubtful situation. Rather, he should be circumcised on [the following] Sunday.

[The following principles apply when] a child is born in the eighth month [of pregnancy]: If the child's nails and hair are completely formed, we assume that this is a completely formed infant that should have been born in the seventh month, but whose birth was delayed. Hence, the baby may be carried on the Sabbath, is not considered to be a stone, and may be circumcised on the Sabbath. If, however, when the baby was born, its hair and nails were incompletely formed, we can be certain that this child is in its eighth month of development and should not have been born until the ninth month, but was born prematurely. Therefore, he is considered as a stone and may not be moved on the Sabbath. Nevertheless, if such an infant remains alive for thirty days, he is considered to be a child who will live and is governed by all the same rules as other infants. Whenever a human child lives longer than thirty days, it is no longer considered to be a stillborn.

[The following rules apply when] a child is born in the seventh month of gestation: If a child is born with his limbs completely formed, we assume that he will live and he should be circumcised on the eighth day [even if it falls on the Sabbath]. If there is a question whether a child was born in the seventh month or in the eighth month, he can be circumcised on the Sabbath. The rationale is: If he was born in the seventh month and his limbs are completely formed, it is appropriate that [his circumcision] supersede [the prohibitions against labor on] the Sabbath. If he was born in the eighth month, circumcising him [does not constitute a violation of the Sabbath prohibitions]. It is like cutting meat, because he is like a stillborn if he is, in fact, born in the eighth month.

When a child's head emerges from his mother's birth canal beyn hash'mashot on Friday, but his entire body does not emerge until after the Sabbath night [has commenced], the child should not be circumcised on the Sabbath. Whenever a child's circumcision does not supersede the Sabbath prohibitions, [such circumcision] also does not supersede the prohibitions of the first day of a festival. It does, however, supersede the prohibitions of the second day of a festival. On Rosh HaShanah, however, it does not supersede [the prohibitions] of either the first or the second day. Similarly, a circumcision that is not carried out at the appropriate time does not supersede [the prohibitions of either of] the two days of Rosh HaShanah.

A sick person should not be circumcised until he regains his health. Seven full days should be counted from the time he regains his health until he is circumcised. When does the above apply? When he recovers from high fever or from a similar illness. If, however, a person's eyes hurt, as soon as his eyes heal he may be circumcised immediately. The same applies in all similar circumstances.

A child whose complexion is very yellowish on the eighth day of his life should not be circumcised until his blood recovers and his complexion returns to that of an ordinary healthy child. Similarly, if his complexion is overly red, as if he had been painted, he should not be circumcised until his blood recovers and his complexion returns to that of an ordinary healthy child. This is an example of sickness, and great care must be taken regarding this matter.

When a woman circumcised her first son and he died because the circumcision sapped his strength, and similarly, circumcised her second son and he also died because of the circumcision, she should not circumcise her third son at the appropriate time. Rather, she should wait until he becomes older and his strength increases. [This applies regardless of whether] the first two children were sired by the same father or not. We should not circumcise a child who is afflicted with any sickness at all, since the danger to life takes precedence over everything. Circumcision can be performed at a later date, while it is impossible to bring a single Jewish soul back to life.