Levítico 15:19 Referencias del Talmud: Jerusalem Talmud Niddah, Jerusalem Talmud Shabbat, Jerusalem Talmud Horayot & Jerusalem Talmud Challah

MISHNAH: Shammai says, every woman’s timing is exact¹A menstruating woman is impure and imparts original impurity to anything she sits on (Lev. 15:19–23). While impurity of food is not mentioned in these verses, it is taken for granted that if she imparts impurity to implements that do not easily become impure, certainly she imparts impurity to food which easily becomes impure. The impurity is defined (v. 19) by “blood is flowing from her flesh”. Shammai holds that a woman notices exactly when her period starts; therefore any food she touches after the onset of her period is impure but anything she had touched before is pure.; Hillel says, from checking to checking²Hillel holds that blood dropscan separate from the uterine wall without necessarily flowing out of the vagina. For him, all food a woman touched between the last time she checked herself thoroughly and the noticed onset of her period are retroactively declared possibly impure., even if that is a long time. But the Sages say following neither of them but for checking to checking to be reduced by 24 hours, and from 24 hours to be reduced by checking³For them, a woman with a regular period does not have to worry about retroactive impurity (Mishnah 2). If she has no regular period, she is expected to check herself from time to time but the retroactive impurity cannot extend to more than 24 hours; the interval of impurity is the smaller of 24 hours and the time from the last thorough check..
Every woman with a regular period⁴Latin svetum, corresponding to Hebrew אורח “regularity”; cf. E. and H. Guggenheimer, Notes on the Talmudic Vocabulary 8–11, Lešonenu 37 (1973), 105–112. follows her exact timing; and if one has intercourse with cloths⁵After intercourse (according to Rashi: before and after intercourse) she wipes herself with a clean cloth which can be inspected the next morning. The connection of the word עדים to the biblical hapax in Is. 64:5 is due to Qimhi; according to Rashi (Is. 64:5), the biblical word is an Aramaism and means “to be discarded”. In Niddah, Rashi seems to to read עֵד “a witness”., this counts as checking and is reduced by 24 hours and by checking.

MISHNAH: Shammai says, every woman’s timing is exact¹A menstruating woman is impure and imparts original impurity to anything she sits on (Lev. 15:19–23). While impurity of food is not mentioned in these verses, it is taken for granted that if she imparts impurity to implements that do not easily become impure, certainly she imparts impurity to food which easily becomes impure. The impurity is defined (v. 19) by “blood is flowing from her flesh”. Shammai holds that a woman notices exactly when her period starts; therefore any food she touches after the onset of her period is impure but anything she had touched before is pure.; Hillel says, from checking to checking²Hillel holds that blood dropscan separate from the uterine wall without necessarily flowing out of the vagina. For him, all food a woman touched between the last time she checked herself thoroughly and the noticed onset of her period are retroactively declared possibly impure., even if that is a long time. But the Sages say following neither of them but for checking to checking to be reduced by 24 hours, and from 24 hours to be reduced by checking³For them, a woman with a regular period does not have to worry about retroactive impurity (Mishnah 2). If she has no regular period, she is expected to check herself from time to time but the retroactive impurity cannot extend to more than 24 hours; the interval of impurity is the smaller of 24 hours and the time from the last thorough check..
Every woman with a regular period⁴Latin svetum, corresponding to Hebrew אורח “regularity”; cf. E. and H. Guggenheimer, Notes on the Talmudic Vocabulary 8–11, Lešonenu 37 (1973), 105–112. follows her exact timing; and if one has intercourse with cloths⁵After intercourse (according to Rashi: before and after intercourse) she wipes herself with a clean cloth which can be inspected the next morning. The connection of the word עדים to the biblical hapax in Is. 64:5 is due to Qimhi; according to Rashi (Is. 64:5), the biblical word is an Aramaism and means “to be discarded”. In Niddah, Rashi seems to to read עֵד “a witness”., this counts as checking and is reduced by 24 hours and by checking.

Rebbi Joḥanan said, Rebbi Jehudah declared impure only in the color of the four kinds of blood⁵In the Babli, 21a, R. Joḥanan is reported to hold that even the Sages agree that a lump in the color of the four types recognized as impure blood (taking red and black together) makes the woman impure; for him the disagreement between the Sages and R. Jehudah refers only to lumps that do not look like blood. R. Joḥanan’s opinion as quoted here is ascribed in the Babli to Rav Jehudah in the name of Samuel.. Rebbi Jacob bar Aḥa, Rebbi Simeon bar Abba, in the name of Rebbi Yose bar Nehorai: Practice follows Rebbi Jehudah. Rebbi Eleazar heard that and said, I do not accept this. Samuel said, practice follows Rebbi Jehudah. Rebbi Ze‘ira said, he did not say that practice follows Rebbi Jehudah but he saw that the rabbis are used to follow Rebbi Jehudah⁶There is no principle involved that practice should follow R. Jehudah; he only stated what he recognized as usual among Babylonian rabbis.. Rebbi Joḥanan in the name of Rebbi Simeon bar Ioḥai: One tears it open. If one finds blood collected there, she is impure, otherwise she is pure⁷In the Babli, 21b, this is a tannaїtic statement of Symmachos attributed to R. Meïr.. Rebbi Eliezer ben Jacob stated, disagreeing with Rebbi Simeon ben Ioḥai: “Blood would be her flow from her genitals,⁸. Lev. 15:19.” not what is in the amnion nor in a lump⁹In the Babli, 21b, this is an amoraic statement attributed to R. Ze‘ira. The explanation of the verse in Sifra Meṣora‘ Parašah 4(4) is rejected by R. Ze‘ira in the Babli, 21b, and by R. Simeon (ben Ioḥai) in Sifra..