1)

(a)The Mishnah now discusses all the possible computations of things that are Ma'alin and/or Poslin, and that are not. The definition of ...

1. ... Ma'alin is that - by adding to it, one renders Kasher a Mikvah that is lacking forty Sa'ah.

2. ... Poslin is that - by adding to it, one renders the same Mikvah Pasul.

(b)The first list begins with snow, hail, frost and ice, about which the Tana rules - Ma'alin ve'Lo Poslin (see Tos. Yom-Tov).

(c)The sort of clay that the Tana includes in the list is - soft clay (mud) that can be poured (see Tos. Yom-Tov).

(d)The other item included in the list is - salt.

2)

(a)R. Yishmael attested before R. Akiva that - snow does not render a Mikvah Kasher.

(b)On the other hand, the men of Meidva told him that - R. Yishmael instructed them to make an entire Mikvah of snow (see Tos. Yom-Tov).

(c)The Halachah is - like the men of Meidva.

(d)R. Yochanan ben Nuri - considers hail-stones like Mayim She'uvim (see Tiferes Yisrael and Rashash).

(e)The Halachah is - like the Tana Kama.

3)

(a)The example the Mishnah now gives to describe Ma'alin ve'Lo Poslin is - where one Sa'ah of one of the above falls into a Mikvah consisting of thirty-nine Sa'ah.

4)

(a)The Tana opens the list of Poslin ve'Lo Ma'alin with water that is either Tamei or Tahor - but that is Mayim She'uvim.

(b)The list continues with Mei Kevashim ...

1. ... Mei Shelakos - water in which olives or vegetables have been pickled [see Tos. Yom-Tov]) and ...

2. ... Mei Shelakos - water in which something has been cooked [see Tos. Yom-Tov]).

(c)The last item on the list is Temed - dregs of wine (the pips and peels) to which water has been added.

(d)Temed belongs to this list - until it turns sour ...

(e)... at which point it falls under the category of fruit-juice, which we are about to discuss.

5)

(a)The example the Mishnah gives to describe Poslin ve'Lo Ma'alin is - a Mikvah lacking a Kurtuv (one sixty-fourth of a Sa'ah) into which one Kurtuv of the above falls.

(b)The Tana rules that - sometimes other liquids and fruit-juice (see Tiferes Yisrael) render the Mikvah Kasher, and sometimes they don't.

(c)The list continues with ...

1. ... Tzir - brine that comes from salted fish and ...

2. ... Muryas - fish-hash - fat that comes from salted fish.

(d)The last item on the list is - Temed that has turned sour.

6)

(a)The items on the current list ...

1. ... do not render the Mikvah Kasher - if for example, one Sa'ah of them fell into a Mikvah containing thirty-nine Sa'ah (see Tos. Yom-Tov).

2. ... render the Mikvah Kasher - if the same Sa'ah fell into a Mikvah containing forty Sa'ah, and one Sa'ah is subsequently removed (see Tos. Yom-Tov).

7)

(a)The Mishnah rules that a Mikvah in which one washes baskets that were used for olives or for grapes, changing the color of the water - remains Kasher, since washing Keilim does not give a Mikvah the Din of Shinuy Mar'eh (see Tos. Yom-Tov) .

(b)R. Yossi rules that - three Lugin of paint-water will disqualify an incomplete Mikvah, but not less, even if it changes the color of the water ....

(c)... because color alone (without substance) is abstract, and cannot disqualify a Mikvah (see Tos. Yom-Tov DH 'R. Yossi Omer ... ').

8)

(a)The Tana rules that wine or olive juice (see Tos. Yom-Tov DH 'u'Mochel') that falls into a Mikvah, causing the water to change color - disqualifies it (see Tos. Yom-Tov DH 'Nafal ... ').

(b)In the event that this happens, assuming the Mikvah contains ...

1. ... less than forty Sa'ah - one must wait for rain-water to be added to the Mikvah, to supplement the forty Sa'ah (see Tos. Yom-Tov).

2. ... more than forty Sa'ah - one can supplement it with Mayim She'uvim, since (Mayim She'uvim cannot invalidate a Kasher Mikvah).

9)

(a)If wine or olive-juice falls into a Kasher Mikvah, changing the appearance of part of it, one may Tovel in it - provided there are forty Sa'ah that remain clear.

(b)If it does not contain forty Sa'ah of clear water, and a person Tovels, even in the part of the Mikvah that has the appearance of water - his Tevilah is invalid.

10)

(a)The Tana Kama rules that if three Lugin of water into which there falls a Kurtuv of wine, giving it the appearance of wine, falls into a Mikvah containing less than forty Sa'ah, which it supplements, the Mikvah remains Kasher (see Tos. Yom-Tov) - because since it looks like wine it is considered wine, and wine (like all fruit-juices) does not render a Mikvah Pasul on account of Mayim She'uvim). And he issues the same ruling ...

(b)in the equivalent case, but where it was a Kurtuv of milk that fell into three Lugin minus a Kurtuv of water, which then fell into the same Mikvah ...

(c)... because the Tana Kama goes after substance too, and even though what fell into the Mikvah looked like water, it was in fact milk.

(d)R. Yochanan ben Nuri maintains that - everything depends on the appearance. Consequently, in the latter case, the Mikvah will be Pasul.

(e)The Halachah is - like the Tana Kama.

11)

(a)The Mishnah now discusses a Mikvah containing exactly forty Sa'ah in which two people Tovel one after the other. The Tana Kama declares the second person still Tamei - because when the first person leaves the Mikvah, some of the water remains on his body, causing the Mikvah to become Chaser (lacking forty Sa'ah).

(b)R. Yehudah declares the second person Tahor too - provided the first person's feet are still in the water, because based on the principle Gud Acheis, all the water on his body is still considered joined to the Mikvah.

(c)The Gemara in Chagigah however, qualifies R. Yehudah's ruling, confining it to Ma'alos de'Rabbanan. Consequently, he ...

1. ... declares the second person Tahor - only if he was anyway Tahor for Chulin and he is now Toveling for Ma'aser Sheini, or if he had already Toveled for Ma'aser Sheini and is now Toveling for Terumah.

2. ... concedes that he remains Tamei - if he was actually Tamei, and is Toveling in order to become Tahor.

(d)The Halachah is - like the Tana Kama (see Tos. Yom-Tov).

12)

(a)The Mishnah rules that someone who Tovels in the same Mikvah of exactly forty Sa'ah after a thick woolen garment (Sagus) was Toveled in it - will be Tahor as long as part of the Sagus is still touching the water.

(b)The name of the author of this Mishnah is - R. Yehudah (see Tos. Yom-Tov and Tiferes Yisrael).

13)

(a)Finally, the Mishnah forbids Toveling a leather cushion or cover in the same above-mentioned Mikvah, unless one removes it from the water with the hem facing downwards ...

(b)- because otherwise, the water that has gathered inside it has become Mayim She'uvim, and pouring it back will invalidate the Mikvah.

14)

(a)One Tovels a bed that is higher than the depths of the Mikvah (whose floor comprises thick mud [see Tos. Yom-Tov]) - by placing it on the floor of the Mikvah, and allowing the legs to sink into the mud.

(b)The bed does not remain Tamei - because as the legs sink into the mud, a film of water precedes it (in which case the legs of the bed are sunk in the water and not in the mud).

15)

(a)In a case where forty Sa'ah of water are spread out over a wide area which renders the Mikvah too shallow to Tovel in - one can stack even bundles of wood or of straw into one side, causing the level of the water to rise.

(b)The Tana says even bundles of wood or of straw - because we might have otherwise thought that the water that seeps into the bundles, in which one cannot Tovel, do not combine with the rest of the water (see Tos. Yom-Tov)

(c)He uses the expression Kovesh with regard to the bundles of wood or straw (places a weight on top of them) - because unless one places weights on top of the bundles, they will merely float around in the shallow water.

(d)The Mishnah suggests that, to prevent a needle from getting lost in the Mikvah - one places it on a step leading down to the Mikvah, and gently moves the water to and fro (see Tos. Yom-Tov), until the water covers the needle for a split second before returning to its former location.