1)

(a)The Mishnah now discusses water from a spring that flows in the vicinity of a trough (that is a K'li). The Tana rules in a case where the water ...

1. ... actually falls into it and spills from it, that - one may not Tovel either inside the trough or in the water that spills from it (see Tos. Yom-Tov).

2. ... flows over the top - one may Tovel both in the water on top of the trough (small vessels) and in the water beyond (see Tos. Yom-Tov).

(b)In the latter case, the water that is still on top of the trough is Kasher, despite the fact that the water inside the trough is the majority (see also Tiferes Yisrael) - because a spring is Kasher for Tevilah even if it is only a Kol Shehu.

(c)If the spring falls into a pool containing forty Sa'ah of rain-water (that is not joined to the spring) - it has the Din of a Mikvah (that requires forty Sa'ah [see Tos. Yom-Tov]).

2)

(a)If one joins the spring to the pool by means of Hamshachah, Zavim and Metzora'im are not permitted to Tovel in it - because the spring water has lost its status of Mayim Chayim (which is what Zavim and Metzora'im require).

(b)The Tana includes in this list - Kidush Mei Chatas.

(c)All three will be permitted however - as soon as it becomes known for sure (see Tos. Yom-Tov) that none of the original water in the pool remains.

3)

(a)According to R. Yehudah, water of a spring that falls over the walls of a vessel or over a bench and continues to flow retains its status of Mei Ma'ayan - in which one may Tovel even whilst it is flowing, and b. even in a Kol-Shehu.

(b)R. Yossi however - gives it the Din of a Mikvah (see Tos. Yom-Tov).

(c)R. Yossi (see Tiferes Yisrael) forbids Toveling on top of the bench - in case one comes to Tovel inside a K'li (see Tos. Yom-Tov).

(d)The Halachah is - like R. Yossi.

4)

(a)The Mishnah discusses a Ma'yan she'Hu Mashuch ke'Nadal - (a spring that flows like a centipede (with a number of tributaries flowing off it).

(b)The Mishnah rules ...

1. ... in a case where a lot of Mayim She'uvin (see Tos. Yom-Tov) is added to it, causing a wider flow that - it retains its status as a Ma'yan.

2. ... in the equivalent case, but where the initial spring is static and the added water causes it to flow that - it has the Din of a Mikvah, (which is Metaher when it is static).

5)

(a)R. Meir considers all seas a Mikvah - in which case the water must be gathered in one place for Tevilah to be effective.

(b)He learns it from the Pasuk in Bereishis - "u'le'Mikveh ha'Mayim Kara Yamim".

(c)R. Yehudah restricts this ruling to the oceans - from the fact that the Pasuk uses the word "Yamim" in the plural, implying that it is only the oceans where many waters the water of many seas mix (See Tiferes Yisrael) that have the Din of a Mikvah, but not other seas.

6)

(a)R. Yossi considers *all the seas* a Ma'yan - with regard to Toveling in them even whilst they are flowing ...

(b)... because the rivers flow into them (see also Tiferes Yisrael).

(c)And the reason that he disqualifies the sea for Zavim, Metzora'im and Mei Chatas is - because when all's said and done, the Torah refers to them as Mikvah.

(d)The Halachah is - like R. Yossi.

7)

(a)The Mishnah draws a distinction between water that flows (Zochlin) and water that drips' (Notfin). The definition of ...

1. ... Zochlin is - a natural river.

2. ... Notfin - rain-water.

(b)The former has the status of - a Ma'yan, the latter of - a Mikvah.

(c)R. Tzadok testified that if Zochlin exceeds Notfin - it retains its status of Ma'yan, even to the extent that ...

(d)... a Zav may Tovel in an area where nineteen Sa'ah of Notfin fell into twenty-one Sa'ah of Zochlin (see Tos. Yom-Tov).

8)

(a)Now the Tana discusses an Ashboren - a Mikvah of gathered water that became breached (see Tos. Yom-Tov) and began to flow.

(b)R. Yehudah permits a Tamei person (see Tos. Yom-Tov) to Tovel in it, even if one stops the flow only temporarily by placing in the breach ...

1. ... a stick or a cane or even ...

2. ... the hand or foot of a Zav or a Zavah.

(c)R. Yossi disagrees - with the latter ruling, permittng only closing the breach with something that is not subject to Tum'ah (disqualifying even the hand or foot of a Tahor person) ...

(d)... and he learns this from the Pasuk in Shemini "Mikveh Mayim Yih'yeh Tahor" - which implies that the Mikvah must become Kasher through something that is Tahor (see Tos. Yom-Tov).

(e)The Halachah is - like Rebbi Yossi.

9)

(a)The Tana rules that if a wave (containing forty Sa'ah [see Tos. Yom-Tov]) detaches itself from the sea and falls on a person - he is Tahor (see Tos. Yom-Tov).

(b)He is only Tahor for Chulin however, but not for Terumah - since whereas the latter requires Kavanah before Toveling, the former does not.

(c)Ma'aser Sheini is comparable - to Terumah in this regard.

10)

(a)The Mishnah rules Tovlin u'Matbilin ba'Charitzin - (square-shaped ditches), u've'Parsas ha'Chamor u'va'Ne'itzin - (triangle-shaped ditches that are wide on top and narrow at the bottom).

(b)Parsas ha'Chamor is - a ditch that is formed by the hooves of donkeys (or any other animal) in muddy ground.

(c)One may Tovel in Parsas ha'Chamor - provided all the hoof-marks in the valley combine to form one ditch.

(d)Besides Toveling Keilim, Matbilin incorporates - Toveling one's hands, where Netilas Yadayim will not suffice (such as for Kidush Mei Parah).

11)

(a)Beis Shamai permit Toveling Keilim in a Chard'lis (see Tiferes Yisrael) - the acronym of 'Har Dalis' [the high part of a mountain]), which therefore means a stream of water that is flowing down a mountain slope.

(b)Beis Hillel agree that it is permitted - provided forty Sa'ah has gathered in one spot ...

(c)... at which point one may place a Mechitzah of Keilim to stop the water, thereby forcing the water to form a pool, in which one is permitted to Tovel.

12)

(a)The Mishnah rules that the Keilim that form the Mechitzah - remain Tamei, since the outside (and the top) is/are not immersed in the Mikvah.

(b)The author of this section of the Mishnah cannot be Beis Hillel - because according to R. Yossi (in the previous Mishnah), Keilim that are subject to Tum'ah, cannot be used as the wall of a Mikvah (and R. Yossi would not argue with Beis Hillel).

(c)The author must therefore be Beis Shamai, who concedes that even if one places such a wall, the Keilim themselves remain Tamei (see also Tiferes Yisrael & Tos. Yom-Tov).