Rambam - 1 Chapter a Day

See the examples given in Chapter 6, Halachah 4, and Chapter 7, Halachah 1.

In Chapter 1, Halachah 4.

One for each transgression, for they are all counted individually. Keritot 2b offers several means of exegesis through which this concept is derived.

I.e., there is a general principle (Hilchot Issurei Bi’ah 17:8, Hilchot Ma’achalot Assurot 9:6)“One prohibition does not take effect while another is in effect.” For example, if one partakes of a mixture of milk and meat from an animal that was not slaughtered properly, one is liable only for partaking of the non-kosher meat. He is not liable for eating milk and meat together. Nevertheless, the three situations which the Rambam proceeds to mention are exceptions.

As exemplified in several of the instances the Rambam cites below.

The Rambam does not give an example of this principle here. In Hilchot Ma’achalot Assurot 8:6, he does, explaining that a person who partakes of a gid hanesheh, a sciatic nerve, of an animal which is treifah is liable for two transgressions. Since when the animal became treifah, its entire body became encompassed in the prohibition, that prohibition also encompasses the gid even though it was prohibited beforehand.
The difference between an issur mosif, the instance mentioned previously, and an issur kollel, this instance, is that an issur mosif has a greater scope of relevance, i.e., it affects a wider range of people. An issur kollel does not affect more people, but it is more encompassing with regard to the forbidden entity, as evident from the example given above (see Rashi, Yevamot 34b). See also Chapter 6, Halachah 4.

He is liable for these three transgressions, because all three transgressions are brought about by the same deed, the slaughter of the animal.

I.e., the windpipe and the gullet.

For an animal slaughtered for the sake of a false divinity may not be offered as a sacrifice to God. Chullin 40a describes the situation more picturesquely, stating: “It is as if he is cutting dust.”

As Hilchot Ma’aseh HaKorbanot 18:6 states, one is liable for slaughtering a consecrated animal outside the Temple Courtyard only when it is fit to be offered as a sacrifice in the Temple.

The slaughter of a fowl is acceptable if only one of the signs, the gullet or the windpipe is slit. Now, if half or less than the windpipe is slit, the animal is considered as living. Thus if half of its windpipe is slit, adding the slightest amount to the slit is considered as ritual slaughter (see Hilchot Shechitah 1:11).

While outside the Temple Courtyard.

I.e., the performance of forbidden labor is prohibited on both these holy days. Thus with one act, he violates two prohibitions, see Chapter 6, Halachah 6.

If, however, his brother passes away childless, it is a mitzvah for him to marry his widow.

For which there is a separate prohibition.

I.e., when the woman married the transgressor’s brother. Significantly, Yevamot 34a, the Rambam’s source, extends the scope of the example, stating that the women married to the two brothers could have been sisters, in which case there would be another prohibition involved, because the prohibition of two sisters is an issur kollel. Rav Yosef Corcus states that the Rambam does not mention that particular, because he does not refer to an issur kollel in this chapter.

I.e., the prohibitions against relations with a woman in the niddah state.

More precisely, as stated in Chapter 5, Halachah 3, this is speaking about a situation where he sodomized a man and that man sodomized him. Nevertheless, since they both acted in different positions, each act of sodomy is considered a separate prohibition.

The Rambam mentions the names of individuals mentioned in the Book of Genesis. In the Biblical narrative, however, not all of them share the family ties he mentions in this hypothetical situation.

The father of Rachel, Jacob’s wife, but who was not related to Zilpa.

These relations are permitted, because, in this hypothetical situation, Lavan does not share a blood relationship with Zilpa.

I.e., the sister of Rachel who is also Jacob’s wife.

I.e., Jacob is prohibited against having relations with Serach on two counts. She is his granddaughter and she is the sister of his wife.

For both of these prohibitions took effect with Serach’s birth.

Jacob's son.

Since Reuven’s marriage caused Serach to be forbidden to his brothers, it also causes her to be forbidden to his father. Rav Yosef Corcus explains that even though the prohibitions need not be alike, i.e., Serach is not forbidden to Reuven’s brothers because of the same prohibition that she is forbidden to Jacob. There must, however, be some similarity with the prohibitions. It is not sufficient that she merely be married.

The Rambam speaks of Jacob’s maternal brother, because afterwards, he speaks of Serach being married by Isaac through the rite of yibbum. If one of Jacob’s paternal brothers had married her, she would be forbidden to Isaac and the marriage between them would not be effective (Kessef Mishneh, based on Hilchot Yibbum VeChalitzah 6:8).

I.e., the prohibition is an issur mossif.

Who is Jacob’s uncle.

Yishmael’s brother and Yaakov’s father.

The Rabbis extended the prohibitions against marriage with relatives and included others who were not forbidden by Scriptural Law, as explained in Hilchot Ishut 1:5. Since the prohibition is only Rabbinic in origin, after the fact the marriage is binding.

Because she was his father's wife. If, however, Jacob did not have any other brothers, Isaac's marriage to Serach would not have increased the number of individuals to whom she was forbidden. Hence, the prohibition would not be considered as an issur mosif.

If Isaac was not alive, she would not be a married woman. In his Commentary to the Mishnah (Keritot 3:5), the Rambam states that it is not necessary that Isaac be alive. That, however, applies only with regard to the prohibition against relations with one's father's wife.

Who is her sister. One is liable for relations with two sisters only while both are alive.

The wording of this halachah parallels the amended text of the Rambam’s Commentary to the Mishnah (op. cit.), as communicated by Rav Kappach in his translation. The standard published text follows a slightly different version.

I.e., in the last instance, Jacob must have paternal brothers for his father's marriage to Serach to bring about an additional prohibition for him. If he does not have paternal brothers, the fact that hypothetically, a prohibition could have been added is not of consequence.

To speak in terms of Biblical relationships: Jacob married Leah, the daughter of Lavan; he also married the daughter of Rachel (Rachel also being Lavan’s daughter and Leah’s sister); and he married the daughter of Lavan’s son. Thus Lavan’s wife is Jacob’s mother-in-law, the mother of his wife’s mother, and the mother of his wife’s father. These marriages are permissible, as stated in Hilchot Issurei Bi’ah 2:14.

I.e., he consecrated the women through the activity of agents, who consecrated all of them at the same time.

I.e., the verse mentions all three prohibitions and uses the same phrase, “They are close.....” to describe all three.

Since the verse uses the phrase “It is a depraved design” to refer to all the prohibitions, one can infer that at times, all three prohibitions are considered as one “depraved design” and one is liable for only one sin-offering (Keritot 14b).

After mentioning the prohibition once, the Torah reiterates the ban, to indicate that one is always liable for this transgression independently (Keritot 15a).

The offspring of the man and his illegitimate daughter.

For both the illegitimate sister and the illegitimate son were fathered by the same man.

Because the same woman gave birth to both that man and his daughter.