Bava Kamma

are the gonorrhoeal discharge of zab, his saliva, his semen virile, his urine and the blood of menstruation, all of which defile whether by 'touching' or by mere 'carrying'.  But why not maintain that the reason here is also because the semen virile of zab cannot possibly be altogether free from particles of gonorrhoea? — If this had been the reason, semen virile should have been placed in juxtaposition to gonorrhoeal discharge. Why then was it placed in juxtaposition to saliva if not on account of the fact that its causing defilement is to be inferred from the law applicable to his saliva? R. Aha of Difti said to Rabina: Behold there is this Tanna who does not employ the principle of Dayyo even when the purpose of the a fortiori would thereby not be defeated. For it was taught: Whence do we learn that mats  become defiled if kept within the tent where there is a corpse? — It is a logical conclusion: For if tiny [earthenware] jugs that remain undefiled by the handling of zab  become defiled when kept within the tent where there is a corpse,  does it not follow that mats, which even in the case of zab become defiled,  should become defiled when kept within the tent where there is a corpse.  Now this reasoning applies not only to the law of defilement for a single day,  but also to defilement for full seven  [days]. But why not argue that the a fortiori well serves its purpose regarding the defilement for a single day,  whilst the principle of Dayyo is to be employed to exclude defilement for seven days? — He [Rabina] answered him: The same problem had already been raised by R. Nahman b. Zachariah to Abaye, and Abaye answered him that it was regarding mats in the case of a dead reptile  that the Tanna had employed the a fortiori, and the text should run as follows: 'Whence do we learn that mats  coming in contact with dead reptiles  become defiled? It is a logical conclusion: for if tiny [earthenware] jugs that remain undefiled by the handling of zab,  become defiled when in contact with dead reptiles,  does it not follow that mats which even in the case of zab become defiled,  should become defiled by coming in contact with dead reptiles?' But whence the ruling regarding mats  kept within the tent of a corpse? — In the case of dead reptiles it is stated raiment or skin,  while in the case of a corpse it is also stated, raiment … skin:  just as in the case of raiment or skin stated in connection with dead reptiles,  mats [are included to] become defiled, so is it regarding raiment … skin stated in connection with a corpse  that mats similarly become defiled. This Gezerah shawah  must necessarily be 'free',  for if it were not 'free' the comparison made could be thus upset: seeing that in the case of dead reptiles [causing defilement to mats], their minimum for causing uncleanness is the size of a lentil,  how can you draw an analogy to corpses where the minimum to cause uncleanness is not the size of a lentil but that of an olive?  — The Gezerah shawah must thus be 'free'. Is it not so? For indeed the law regarding dead reptiles is placed in juxtaposition to semen virile as written, Or a man whose seed goeth from him,  and there immediately follows, Or whosoever toucheth any creeping thing. Now in the case of semen virile it is explicitly stated, And every garment, and every skin, whereon is the seed of copulation.  Why then had the Divine Law to mention again raiment or skin in the case of dead reptiles?  It may thus be concluded that it was [inserted] to be 'free' [for exegetical purposes].  Still it has so far only been proved that one part [of the Gezerah shawah]  is 'free'. This would therefore be well in accordance with the view maintaining  that when a Gezerah shawah is 'free', even in one of its texts only, an inference may be drawn and no refutation will be entertained. But according to the view holding  that though an inference may be drawn in such a case, refutations will nevertheless be entertained, how could the analogy [between dead reptiles and corpses] be maintained?  — The verbal congruity in the text dealing with corpses is also 'free'. For indeed the law regarding corpses is similarly placed in juxtaposition to semen virile, as written, And whoso toucheth any thing that is unclean by the dead or a man whose seed goeth from him etc.  Now in the case of semen virile it is explicitly stated, And every garment, and every skin, whereon is the seed of copulation. Why then had the Divine Law to mention again raiment … skin in the case of corpses?  It may thus be concluded that it was [inserted] to be 'free' for exegetical purposes.  The Gezerah shawah is thus 'free' in both texts. Still this would again be only in accordance with the view maintaining  that when an inference is made by means of reasoning [from an analogy] the subject of the inference is placed back on its own basis.  But according to the view that when an inference is made [by means of an analogy] the subject of the inference must be placed on a par with the other in all respects, how can you establish the law [that mats kept in the tent of a corpse become defiled for seven days,  since you infer it from dead reptiles where the defilement is only for the day]?  — Said Raba: Scripture states, And ye shall wash your clothes on the seventh day,  to indicate that all defilements in the case of corpses cannot be for less than for seven [days]. But should we not let Tooth and Foot involve liability for damage done [even] on public ground because of the following a fortiori: If in the case of Horn  where [even] for damage done on the plaintiff's premises only half payment is involved, there is yet liability to pay for damage done on public ground, does it not necessarily follow that in the case of Tooth and Foot where for damage done on the plaintiff's premises the payment is in full, there should be liability for damage done on public ground? — Scripture, however, says, And it shall feed in another man's field,  excluding thus [damage done on] public ground.