Niddah

An enquiry was addressed to  R. Nahman: [Is the examination at] regular menstrual periods Pentateuchal  or only Rabbinical?  The latter replied: Since our colleague Huna citing Rab ruled, If a woman who has a settled period did not make an examination when that period arrived but later on  observed a discharge, she must take into consideration the possibility [of a discharge] on the date of the settled period,  and also the possibility of [twenty-four hours retrospective uncleanness] on account of her observation.  Thus  it clearly follows that [the examination at] regular menstrual periods is Pentateuchal. There are others who say that he  replied thus: The reason then  is that she had 'observed a discharge,'  but if she had not observed one the possibility  need not be taken into consideration. Thus  it follows clearly that [the examination at] regular menstrual periods is only Rabbinical. It was stated: If a woman had a settled period, and when the time of that period arrived she did not make the examination and later she did make one, Rab ruled: If on examination she found that she was unclean she is unclean but if she found that she was clean she remains clean. Samuel, however, ruled, Even if on examination she found herself clean she is deemed unclean, since the guest  comes at the usual time. Must it be assumed that they  differ on [the question of the necessity for an examination at] regular menstrual periods, one Master  holding that it is Pentateuchal  and the other Master  maintaining that it is only Rabbinical?  R. Zera replied: Both  may agree that  [the examination at] regular menstrual periods is Pentateuchal, but  one ruling  refers to a woman who examined herself within the period of the duration of her menstruation  while the other  refers to a woman who did not examine herself within the period of the duration of her menstruation.  R. Nahman b. Isaac maintained: They  differ on the very question of [the necessity for an examination at] the regular menstrual periods, one Master  holding that it is Pentateuchal  while the other Master  maintains that it is only Rabbinical. R. Shesheth observed: [The discussion here] is analogous to that of the following Tannas: [For it was taught:] R. Eliezer  ruled, She  is to be regarded as menstrually unclean,  while R. Joshua  ruled: Let her be examined.  And these Tannas  differ on the same principle as the following Tannas. For it was taught: R. Meir ruled, She  is to be regarded as menstrually unclean,  while the Sages  ruled, Let her be examined.  Abaye observed, We also learnt to the same effect. For we learnt: R. Meir ruled, If a woman was in a hiding place  when the time of her regular period arrived and she did not examine herself, she is nevertheless clean, because fear suspends the menstrual flow.  The reason then  is that there was fear, but if there had been no fear she would have been deemed unclean. Thus it clearly follows [that the necessity for an examination at] regular periods is Pentateuchal. May it be assumed that the following Tannas also differ on the same principle? For it was taught: If a woman observed some blood [that might be] due to a wound,  even if this occurred during her usual period of menstruation, she is deemed to be clean;  so R. Simeon b. Gamaliel. Rabbi ruled: If she has a regular period  she  must take her period into consideration.  Now do they not differ on this principle, one Master  holding that [the examinations at] the regular periods are Pentateuchal, while the other Master  holds that they are only Rabbinical? — Rabina replied: No; both may agree that [the examinations at] the regular periods are only Rabbinical, but it is on the question whether the interior of the uterus is unclean  that they differ. R. Simeon b. Gamaliel holds that the woman is clean  but the blood  is unclean because it comes through the uterus,  and Rabbi  in effect said to him: If  you take into consideration the possibility of her usual menstrual flow, the woman also should be unclean,  and if  you do not take into consideration the possibility of her usual menstrual flow, [the blood also should be clean since] the interior of the uterus  is clean. MISHNAH. BETH SHAMMAI RULED: A WOMAN NEEDS TWO  TESTING-RAGS FOR EVERY INTERCOURSE,  OR SHE MUST PERFORM IT IN THE LIGHT OF A LAMP.  BETH HILLEL RULED: TWO TESTING-RAGS  SUFFICE HER FOR THE WHOLE NIGHT.