Niddah, Chapter 4, Mishnah 1. The mishnayos here deal with a woman who miscarries and with the question of when such a discharge carries the tumah of childbirth. Our mishnah introduces a decisive factor: how much time passed since conception. Before a certain point in the pregnancy there is nothing yet that halachah can call a child, and after that point there is.
By way of background: a woman who gives birth to a male is temeiah for seven days and then has thirty three days of dam tohar; for a female it is fourteen days of tumah followed by sixty six days of dam tohar.
The fortieth day and the forty first
The mishnah begins with the case of "Hamapeles leyom arba'im": the discharge occurred on day forty of the pregnancy, or anywhere earlier within that opening stretch of forty days counted from conception. In such a case the ruling is "einah chosheshes levalad": no suspicion of a birth attaches to her at all. That entire first period is when the embryo is still taking shape, so whatever came out has not yet reached the halachic definition of a valad.
If, however, the discharge came "leyom arba'im ve'echad", on day forty one or later, then "teishev lezachar velinekeivah uleniddah". Three separate possibilities are now treated stringently at once: perhaps a boy was born, perhaps a girl, and perhaps she has become a niddah. The practical result is fourteen days of certain tumah, after which any blood she sees receives no status of dam tohar; it is reckoned as the blood of a niddah, leaving her temeiah on that account. Why pile up all three? Because at so early a stage the matter lies beyond identification. Nothing about what emerged reveals its gender, and it may equally be that no fetus was involved and only blood came out.
The opinion of Rabbi Yishmael"Rabbi Yishmael omeir": Rabbi Yishmael divides the cases. Beginning with "yom arba'im ve'echad", only two chumros rest upon her, those of a mother of a boy and those of a niddah, in the words of the mishnah, "teishev lezachar uleniddah". The full set of three, "teishev lezachar velinekeivah uleniddah", takes effect only from "yom shemonim ve'echad", the eighty first day.
His reasoning is stated in the mishnah: "shehazachar nigmar le'arba'im ve'echad, vehanekeivah lishmonim ve'echad", a male fetus completes its formation after forty one days, while a female fetus completes its formation only after eighty one days. Accordingly, a miscarriage between the forty first and the eightieth day cannot possibly be a female, since a female is not yet formed, and there is no reason to keep the stringencies of a female birth.
The ruling of the chachamim
"Vachachamim omrim": the chachamim hold otherwise. In their view, "echad beriyas hazachar" and "echad beriyas hanekeivah": whether the fetus be male or female, the process of coming into being runs the same course, and in either case, "zeh vezeh le'arba'im ve'echad", it reaches completion after forty one days. The line drawn between day forty one and day eighty one thus falls away altogether, and one rule governs the entire period from the forty first day onward: a woman who loses her pregnancy takes upon herself the chumros of a mother of a boy, of a mother of a girl, and of a niddah.
The accepted halachah is in accordance with the chachamim.
"Rabbi Yishmael omeir": Rabbi Yishmael divides the cases. Beginning with "yom arba'im ve'echad", only two chumros rest upon her, those of a mother of a boy and those of a niddah, in the words of the mishnah, "teishev lezachar uleniddah". The full set of three, "teishev lezachar velinekeivah uleniddah", takes effect only from "yom shemonim ve'echad", the eighty first day.
His reasoning is stated in the mishnah: "shehazachar nigmar le'arba'im ve'echad, vehanekeivah lishmonim ve'echad", a male fetus completes its formation after forty one days, while a female fetus completes its formation only after eighty one days. Accordingly, a miscarriage between the forty first and the eightieth day cannot possibly be a female, since a female is not yet formed, and there is no reason to keep the stringencies of a female birth.
The ruling of the chachamim
"Vachachamim omrim": the chachamim hold otherwise. In their view, "echad beriyas hazachar" and "echad beriyas hanekeivah": whether the fetus be male or female, the process of coming into being runs the same course, and in either case, "zeh vezeh le'arba'im ve'echad", it reaches completion after forty one days. The line drawn between day forty one and day eighty one thus falls away altogether, and one rule governs the entire period from the forty first day onward: a woman who loses her pregnancy takes upon herself the chumros of a mother of a boy, of a mother of a girl, and of a niddah.
The accepted halachah is in accordance with the chachamim.