The Gemara asks that Rav Yehudah said that Nivreches is a B'kia, whereas the B'raysa seems to indicate that Nivreches and B'Kia are not the same thing. The Gemara answers by saying that there are two types of pool necessary for washing clothes in a courtyard, a Giha and a Bar Giha. The question remains, how does this answer the contradiction that bothered the Gemara in the first place.

It seems from the Gemara, that the once we become aware of the fact that there are two types of pool, this alone is sufficient to answer the contradiction. However, it is unlikely that the Gemara was unaware of the fact that two pools are used for washing clothes, so I would suggest that the Gemara was unaware that it is necessary to refer to each pool separately. The Gemara assumed that it is obvious that both pools have the same Halachah. Hence, when the Gemara saw that the Tana refers to both Nivreches and B'kia the Gemara understood that this indicates that a Nivreches is not a pool, since we knew that a B'kia is a pool, and we assumed that both these pools are included in the same word. When the Gemara answers Giha u'Var Giha, the Gemara is telling us that the Tana felt it necessary to refer to each one separately, so that we should not think that they have different Halachos. However the Tana of the Mishnah was happy to tell us that Nivreches is Mutar and if so Kol sh'Kein B'kia.

However, at the start the Gemara did not know that Nivreches is a pool so Rav Yehudah came to tell us that it is a pool, and he did not feel it necessary to explain that Nivreches is not more stringent because the Mishnah says that Nivreches is also Mutar.

The Tana of the Brasysa was more explicit and was not happy to say just Nivreches, perhaps because he was worried that we may think that a Nivreches is a B'kia, and a Nivreches is not permitted.

Dov Freedman