Berakhot

so that a woman who becomes niddah during sexual intercourse does not require a ritual ablution, but an ordinary ba'al keri does require ritual ablution! — Read [in the Mishnah] not: [R. JUDAH SAYS,] HE SAYS THE BLESSING, but 'He says mentally'. But does R. Judah [in any case] prescribe saying mentally? Has it not been taught: A ba'al keri who has no water for a ritual ablution recites the Shema' without saying a blessing either before or after, and he eats bread and says a blessing after it. He does not, however, say a blessing before it, but says it mentally without uttering it with his lips. So R. Meir. R. Judah says: In either case he utters it with his lips? — Said R. Nahman b. Isaac: R. Judah put it on the same footing as the halachoth of Derek Erez,  as it has been taught: 'And thou shalt make them known to thy children and thy children's children', and it is written immediately afterwards, 'The day on which thou didst stand before the Lord thy God in Horeb'. Just as there it was in dread and fear and trembling and quaking, so in this case too  it must be in dread and fear and trembling and quaking. On the basis of this they laid down that sufferers from gonorrhoea, lepers, and those who had intercourse with niddoth are permitted to read the Torah, the Prophets and the Hagiographa, and to study the Mishnah, [Midrash]  the Talmud,  halachoth and haggadoth, but a ba'al keri is forbidden.  R. Jose said: He may repeat those with which he is familiar, so long as he does not expound the Mishnah. R. Jonathan b. Joseph said: He may expound the Mishnah but he must not expound the Talmud.  R. Nathan b. Abishalom says: He may expound the Talmud also, provided only he does not mention the divine names that occur  in it. R. Johanan the sandal-maker, the disciple of R. Akiba, said in the name of R. Akiba: He should not enter upon the Midrash at all. (Some read, he should not enter the Beth Ha-midrash at all.) R. Judah says: He may repeat the laws of Derek Erez.  Once R. Judah after having had a seminal issue was walking along a river bank, and his disciples said to him, Master repeat to us a section from the laws of Derek Erez, and he went down and bathed and then repeated to them. They said to him: Have you not taught us, Master, 'He may repeat the laws of Derek Erez'? He replied: Although I make concessions to others, I am strict with myself. It has been taught: R. Judah b. Bathyra used to say: Words of Torah are not susceptible of uncleanness. Once a certain disciple was mumbling over against R. Judah b. Bathyra.  He said to him: My son, open thy mouth and let thy words be clear, for words of Torah are not susceptible to uncleanness, as it says, Is not My word like as fire.  Just as fire is not susceptible of uncleanness, so words of Torah are not susceptible of uncleanness. The Master said: He may expound the Mishnah, but he must not expound the Talmud. This supports R. Ila'i; for R. Ila'i said in the name of R. Aha b. Jacob, who gave it in the name of our Master:  The halachah is that he may expound the Mishnah but he must not expound the Talmud. The same difference of opinion is found among Tannaim. 'He may expound the Mishnah but he must not expound the Talmud'. So R. Meir. R. Judah b. Gamaliel says in the name of R. Hanina b. Gamaliel: Both are forbidden. Others report him as having said: Both are permitted. The one who reports 'Both are forbidden' concurs with R. Johanan the sandal-maker; the one who reports, 'both are permitted' concurs with R. Judah b. Bathyra. R. Nahman b. Isaac said: It has become the custom  to follow these three elders, R. Ila'i in the matter of the first shearing,  R. Josiah in the matter of mixed kinds, and R. Judah b. Bathyra in the matter of words of Torah. 'R. Ila'i in the matter of the first shearing', as it has been taught: R. Ila'i says: The rule of the first shearing applies only in Palestine. 'R. Josiah in the matter of mixed kinds', as it is written, Thou shalt not sow thy vineyard with two kinds of seeds.  R. Josiah says: The law has not been broken until one sows wheat, barley and grape kernels with one throw.  'R. Judah b. Bathyra in the matter of words of Torah,' as it has been taught: R. Judah b. Bathyra says: Words of Torah are not susceptible of uncleanness. When Ze'iri came [from Palestine]. he said: They have abolished the ritual ablution. Some report him to have said: They have abolished the washing of hands. The one who reports 'they have abolished the ritual ablution' concurs with R. Judah b. Bathyra. The one who reports 'they have abolished the washing of hands' is in accord with R. Hisda, who cursed anyone who went looking for water at the hour of prayer. Our Rabbis taught: A ba'al keri on whom nine kabs  of water have been thrown is clean. Nahum a man of Gimzu  whispered it to R. Akiba, and R. Akiba whispered it to Ben 'Azzai, and Ben 'Azzai went forth and repeated it to the disciples in public. Two Amoraim in the West differed in regard to this, R. Jose b. Abin and R. Jose b. Zebida. One stated: He repeated it, and one taught, He whispered it. The one who taught 'he repeated it' held that the reason [for the concession] was to prevent neglect of the Torah and of procreation. The one who taught 'he whispered it' thought that the reason was in order that scholars might not always be with their wives like cocks. R. Jannai said: I have heard of some who are lenient in this matter,  and I have heard of some who are strict in it;  and if anyone is strict with himself in regard to it, his days and years are prolonged. R. Joshua b. Levi said: What is the sense of those who bathe in the morning? [He asks], What is the sense! Why, it was he himself who said that a ba'al keri is forbidden [to occupy himself] with the words of the Torah! What he meant is this: What is the sense of bathing in forty se'ahs  when one can make shift with nine kabs? What is the sense of going right in when throwing the water over one is sufficient? R. Hanina said: They put up a very valuable fence by this,  as it has been taught: Once a man enticed a woman to commit an offence and she said to him: Vagabond,  have you forty se'ahs to bathe in, and he at once desisted. Said R. Huna to the disciples: My masters, why do you make so light of this bathing? Is it because of the cold? You can use the baths! Said R. Hisda to him: Can ablution be performed in hot baths? — He replied: R. Adda b. Ahabah is of the same opinion as you. R. Ze'ira used to sit in a tub of water in the baths and say to his servant, Go and fetch nine kabs and throw over me. R. Hiyya b. Abba said to him: Why, sir, do you take this trouble, seeing that you are sitting in [that quantity of] water? — He replied: The nine kabs must be like the forty se'ahs: just as the forty se'ahs are for immersion and not for throwing, so the nine kabs are for throwing and not for immersion. R. Nahman prepared an ewer holding nine kabs.  When R. Dimi came, he reported that R. Akiba and R. Judah Glostera  had said: The rule,  was laid down only for a sick person who has an emission involuntarily, but for a sick person who has a voluntary emission  forty se'ahs [are required]. Said R. Joseph: R. Nahman's ewer was broken.  When Rabin came, he said: The thing took place in Usha