QUESTIONS: The Gemara cites the Mishnah in Mikva'os (5:6) which states that if a wave with forty Se'ah of water gushes out of the sea and falls onto a person, the person becomes Tahor. The Gemara explains that this form of Tevilah is valid only when the person is at the "head" (Roshin) of the wave, which means that the wave meets him as it hits the ground, but not when the crest of the wave passes over him while it is still lifted above the ground (Kipin). The latter is not a valid form of Tevilah because it is like immersing "in the air."
The Gemara explains that one might have thought that the Rabanan prohibited Tevilah even in the Roshin of a wave so that a person not think that he is permitted to immerse in a "Chardalis," a waterfall or rushing stream of rainwater.
RASHI explains that the reason why immersion in a Chardalis of rainwater is not valid is because the stream flows at a steep incline, or "Katafras," and water on an incline cannot be viewed as a single cohesive unit of water. That is, a Chardalis is viewed as a collection of individual drops of water, and as such it lacks the minimum required volume of a Mikvah (forty Se'ah). The Gemara says that one might have thought that if he is permitted to immerse in a wave which contains forty Se'ah of water, he is also permitted to immerse in a Chardalis with forty Se'ah of water (which certainly is not a valid Tevilah since the water is not considered joined together to make forty Se'ah).
When Rashi discusses the identical Sugya as it appears in Chulin (31b), he stops at this point. Here in Chagigah, however, he adds that there is an additional problem with immersion in a stream of rainwater, besides the problem of Katafras: the water of a Chardalis cannot be Metaher a person because it is "Zochalin," flowing, and rainwater must be stationary and gathered in one place in order to be Metaher.
There are a number of difficulties with the Gemara and Rashi.
First, why is immersion in a wave a valid Tevilah? The immersion should be invalid because of the problem of Zochalin since the wave is flowing, and because of the problem of Katafras, since the water in the wave descends at an incline.
Perhaps the problem of Zochalin does not invalid the Tevilah in this case because the Mishnah in Mikva'os (5:4) says that seawater is like springwater and not like rainwater: it is Metaher a person even when it is flowing. Since the wave comes from the sea, it may be Metaher even when it is Zochalin. However, the problem of Katafras remains. How can the forty Se'ah of water in the wave (either in the Roshin or Kipin) be considered a valid Mikvah?
Second, why does Rashi mention that immersion in a Chardalis is not valid because the water travels at an incline (Katafras)? The Chardalis is comprised of rainwater, and Tevilah in such water obviously is invalid because of the problem of Zochalin. There is no need for Rashi to add the additional reason of Katafras. Why does Rashi here add the reason of Zochalin only as an afterthought, and in Chulin (31b) omit the reason of Zochalin altogether? (TOSFOS to Chulin 31b, DH Gezeirah)
Third, why in general did the Chachamim need to teach that flowing rainwater (Zochalin) may not be used for Tevilah? Every instance of flowing rainwater is invalid for another reason -- it is a Katafras and is not considered to contain forty Se'ah of water in one place.
ANSWERS: There appears to be a basic disagreement between Rashi and Tosfos about how to understand the Mishnah of "Gal she'Nitlash," immersion in a wave, which has important implications for the questions posed above.
The Acharonim point out that the Mishnah of "Gal she'Nitlash" seems to be self-contradictory. The Mishnah says that Tevilah in the wave is valid, even though the water is Zochalin, apparently because the seawater of the wave is considered like springwater (which is valid for Tevilah even while it flows). On the other hand, springwater is Metaher even with less than forty Se'ah, and yet the Mishnah says that the wave is Metaher because it contains forty Se'ah! If the wave-water is considered like springwater, then it should be Metaher with less than forty Se'ah. The fact that it requires forty Se'ah implies that it is not considered like springwater but rather like rainwater. Why, then, does the Mishnah say that it is Metaher when it is Zochalin?
The Acharonim offer different approaches to resolve this question. The TAZ (YD 201:5) explains that the wave is considered part of the sea since it is still attached to the sea, and, like springwater, it is valid for Tevilah while it flows. It does not actually need to contain forty Se'ah, but it does need to cover the person entirely in order to be Metaher him. Since forty Se'ah of water are usually required to cover a person, the Mishnah mentions forty Se'ah as a practical consideration. (See also ME'IRI here.)
The SHACH (ibid.) disagrees with this approach. He maintains that the case of "Gal she'Nitlash" refers to a wave which is entirely separated from the sea. Since it no longer is part of the sea, it needs forty Se'ah to be a valid Mikvah, like a collection of rainwater. However, it is Metaher b'Zochalin because it is similar to springwater in the sense that its natural tendency is to move (that is, it has inherent energy moving it, in contrast to rainwater which just falls and collects in one place). (See also TOSFOS YOM TOV in Mikva'os in the name of the MAHARIK.)
(Other approaches to this question are suggested by the RASHBA (in Toras ha'Bayis, Hilchos Mikva'os, and as cited by the TOSFOS YOM TOV, ibid., in the name of the ROSH), TOSFOS CHADASHIM, MISHNAH ACHARONAH, and others.)
The underlying point of dispute between Rashi and Tosfos may depend on the answer to this question.
(a) Rashi apparently understands that the wave is considered springwater. Accordingly, there is no problem of Katafras or Zochalin in a wave, because springwater is Metaher with Zochalin and with less than forty Se'ah (that is, even if it is a Katafras and its water does not combine to make one large, forty-Se'ah Mikvah). This answers the first question.
To answer the second question (why Rashi writes that Tevilah in a Chardalis is invalid because of Katafras), TOSFOS (DH Nigzor) quotes RABEINU ELCHANAN who explains Rashi's logic. If water in a wave is normally Metaher b'Zochalin like springwater, then why does the Gemara say that a person might confuse seawater with a Chardalis of rainwater and use rainwater which is Zochalin? If there is such a concern, the use of springwater which is Zochalin should never be permitted, lest one use rainwater which is Zochalin! It must be that the Gemara's concern is that if Tevilah in a wave is permitted, one might think Tevilah in a Katafras is permitted (but not that one might think Tevilah in rainwater which is Zochalin is permitted). Accordingly, Rashi expresses the opinion of the Taz that a wave is part of the ocean and is the same as ordinary springwater.
How, though, is it possible to immerse in a Katafras of rainwater which is not invalid for Tevilah because of Zochalin? If it is Katafras, it is also Zochalin! The answer is that such a scenario exists in a case similar to the case recorded later (end of 19a) in which a proper Mikvah (with forty Se'ah) sits at the top of a hill and a Chardalis descends from it. If the water that flows in a Chardalis is considered to be attached to the water in the Mikvah at the top of the hill, then one may immerse in the stream because it is considered to be part of the Mikvah (which is not flowing) at the top of the hill, even though it is a Katafras (TIFERES YAKOV to Chulin 31b). When Rashi here adds that in addition to Katafras, one may not immerse in a Chardalis because it is Zochalin, he refers to an ordinary Chardalis of rainwater (which is not connected to a Mikvah -- similar to the wave in the case of the Gemara here). Since it is not important to know that Halachah in order to understand the Gemara here, Rashi in Chulin leaves it out altogether.
What is Rashi's opinion with regard to the third question -- why did the Chachamim need to teach that flowing rainwater (Zochalin) may not be used for Tevilah, when every instance of flowing rainwater is already invalid because it is a Katafras? Rashi (DH Chardalis; Avodah Zarah 72a, DH Katafras; Shabbos 31b, DH Chardalis) emphasizes that a Katafras is a very steep slope. He apparently means that the difference between Katafras and Zochalin is the gradient of the slope: a slight slope, which causes the water to run but not to rush swiftly, is Zochalin but not Katafras.
(b) TOSFOS (Chulin 31b) disagrees with Rashi and explains that a Chardalis is not valid for Tevilah simply because it is Zochalin. Since Tosfos understands the Mishnah of "Gal she'Nitlash" differently, he addresses the questions differently from Rashi.
Tosfos understands (like the Shach) that the wave in the Mishnah's case is entirely separated from the sea and no longer has the status of springwater. Since the wave is cut off from the sea, it is considered like rainwater and needs forty Se'ah to be Metaher a person. Nevertheless, it is Metaher b'Zochalin because it is naturally propelled with its own force, unlike rainwater (which simply falls). Any water that moves as a result of its own force is able to be Metaher even while it flows (see also TOSFOS to Shabbos 109a, DH Rebbi Yosi). Thus, wave-water is an exception to the rule: it is a form of non-springwater which nevertheless is Metaher while it flows. Since it is not springwater, it is logical that the Chachamim would prohibit Tevilah in a rushing wave lest one mistakenly perform Tevilah in a Chardalis of rainwater which is rushing past; he might think that there is no difference between a wave which rushes past and a steam of rainwater which rushes past. He will assume that any water which rushes past in its natural course is Metaher b'Zochalin. In truth, however, the rainwater stream is not Metaher b'Zochalin, because its movement derives solely from the force of gravity (the slope of a hill) rather than tidal, geothermal, or other geohydrological forces. This explains why Tosfos understands that one might confuse immersing in a wave with immersing in normal rainwater which is Zochalin.
According to Tosfos, why is there no concern of Katafras with immersion in a wave? Since Tosfos maintains that the wave indeed must contain forty Se'ah of water, and it is considered like rainwater, the fact that it is falling from the air (Katafras) should render it invalid for Tevilah!
It appears from Tosfos in Chulin (31b; see RASHASH there) that all of the water in the slope of a Katafras itself is considered attached; only the stationary water which stands above or below the slope is not considered a part of the water in the Katafras. Consequently, if there would be forty Se'ah in the slope, Tevilah in the Katafras would be valid if not for the additional problem of Zochalin. One may immerse in a wave, because a wave which contains forty Se'ah of water does not have the problem of Zochalin (as explained above), and the problem of Katafras does not invalidate it. This answers the first question (why the wave itself is not invalid because of Katafras).
The answer to the third question, according to Tosfos, is obvious as well. The Pesul of Zochalin is necessary even though there is a Pesul of Katafras, because Zochalin invalidates Tevilah in the water on the slope when there are forty Se'ah of water on the slope. (Tosfos himself writes this explicitly in Chulin, ibid.)
(c) The above approaches express how Rashi and Tosfos answer the third question (what the difference is between the Pesul of Zochalin and the Pesul of Katafras). It is interesting to note that an entirely new approach to this subject is printed in the HAGAHOS HA'GRA (YD 201:6) in the name of the RIVASH. According to that approach, the two Pesulim of Zochalin and Katafras are indeed one and the same! The reason why rainwater cannot be Metaher while it flows is because it is Katafras -- a flowing body of water is invalid for Tevilah. The forty Se'ah which it contains cannot be combined to produce one cohesive Mikvah; instead, it is like thousands of tiny droplets of water (that happen to be next to each other). Tevilah in Zochalin is like Tevilah in a Mikvah which lacks forty Se'ah of water.
Springwater, in contrast, is Metaher b'Zochalin. Since it is not necessary to have forty Se'ah of springwater for Tevilah, and even the smallest amount suffices as long as it covers the object being immersed, immersion in flowing springwater is valid. Katafras (that is, Zochalin) does not render it invalid for Tevilah because Katafras merely breaks it up into drops of water of less than forty Se'ah each, and forty Se'ah is not necessary for immersion in springwater!
(RASHI himself in Shabbos (109a, DH Kol ha'Yamim) appears to cite an explanation similar to that of the Rivash. After a lengthy explanation of the Gemara, he says, "I have not learned this way." Although he does not state explicitly which part of the explanation he rejects, perhaps he rejects the approach of the Rivash, who equates the Pesul of Zochalin with the Pesul of Katafras.)
OPINIONS: The Gemara concludes that when one washes his hands for Chulin, his act of washing is valid for Chulin even if he does not have Kavanah, specific intent, to wash for Chulin.
What is the Halachah with regard to eating bread of Chulin after one washes his hands without Kavanah (for example, a pail of water fell on his hands and he did not have specific intent to wash in order to eat bread)?
(a) The BEIS YOSEF (OC 159) writes that most Rishonim and Poskim rule that one does not need Kavanah during Netilas Yadayim in order to eat bread. Hence, the act of Netilas Yadayim is valid when a pail of water falls on one's hands.
(b) The RASHBA (in Toras ha'Bayis 6:4 and Mishmeres ha'Bayis there, and Teshuvos 1:510) writes that the Gemara and Tosefta imply that Kavanah is necessary in order for one's Netilas Yadayim to be valid. He cites the Gemara in Chulin which says that one may wash his hands in the morning and have in mind to eat bread later in the day, as long as he stipulates that he plans to eat later with this Netilas Yadayim. It is clear that this Netilas Yadayim remains valid only when he is careful to avoid touching anything which would render his hands Tamei. Without such caution, no stipulation would be effective (Rashi, Rambam). Why, then, must one stipulate at the time he washes in the morning that he plans to eat later? If no Kavanah is necessary for Netilas Yadayim, then even without a stipulation his Netilas Yadayim should be valid. Even if water merely falls on his hands, he may eat later in the day as long as he was careful to keep his hands Tahor. It must be that in order for the Netilas Yadayim to be valid and enable him to eat bread, he must have specific intent that the purpose of the washing is to enable him to eat bread.
Moreover, the Tana Kama in the Tosefta (in Yadayim) says that if one person poured water on the hands of another person, and one of them had in mind that the washing was in order to eat bread, the Netilas Yadayim is valid. Rebbi Yosi there disagrees and says that it is not valid. The Rashba points out that everyone, even the Tana Kama in the Tosefta, requires that at least one person (the one who pours the water, or the one whose hands are washed) have Kavanah.
How does the Rashba understand the Gemara here which says that one does not need Kavanah when he washes his hands for Chulin? The Rashba suggests several answers:
1. In TESHUVOS (ibid.), the Rashba suggests that the Gemara refers to one who wants to handle Chulin Al Taharas Terumah; that is, he wants to conduct himself in a stringent manner and treat all of his Chulin food as though it were Terumah. In such a case, the Rabanan were not so stringent as to give the Chulin the full status of Terumah so that its Netilas Yadayim requires Kavanah. In contrast, the Rabanan instituted that when one wants to eat bread of Chulin (whether or not he treats it like Terumah), he must wash his hands because of "Serach Terumah" (see Insights to Chagigah 18:2:a). They gave the bread a status similar to that of Terumah (for which Netilas Yadayim requires Kavanah), but they did not make it completely like Terumah (which requires the Kavanah of both the person who pours the water and the person whose hands are washed, in contrast to Chulin which requires only the Kavanah of one of them).
2. In TORAS HA'BAYIS, the Rashba adds that the Gemara here follows the opinion of Rebbi Akiva who says that a person's hands can become a Rishon l'Tum'ah (for example, when one places his hands into a house afflicted with a Nega of Tzara'as). Accordingly, the hands need to be washed because they are a Rishon l'Tum'ah and can be Metamei other Chulin (and not because of "Serach Terumah" or because they are "Stam Yadayim" which are only a Sheni l'Tum'ah). Thus, in a case in which one's hands are a Rishon l'Tum'ah, one needs Netilas Yadayim even when he touches (and not only eats) Chulin, because a Rishon l'Tum'ah can be Metamei an object of Chulin. In order to become permitted to touch Chulin in such a case, one does not need Kavanah when he washes his hands.
3. The ME'IRI explains that when the Mishnah and Gemara here refer to Netilas Yadayim of Chulin, they do not mean the common Netilas Yadayim done before eating bread at a meal. The common Netilas Yadayim is unrelated to the subject of the Mishnah which discusses Tum'ah and Taharah. Rather, the Mishnah means that even Chulin can become Tamei from a Sheni l'Tum'ah when a person eats bread of Chulin with hands that are Tamei (as Sheni l'Tum'ah). When he eats the bread of Chulin, that food can become Tamei as well. (The Mishnah's requirement of Netilas Yadayim is entirely unrelated to the laws of washing for a meal. See Insights to Chagigah 18:2.)
Although the RE'AH in BEDEK HA'BAYIS disagrees with the Rashba, the RITVA (Chulin 106b) mentions that the Netilas Yadayim for a meal of Chulin needs Kavanah.
HALACHAH: The SHULCHAN ARUCH (OC 159:13) rules that, l'Chatchilah, when one performs Netilas Yadayim he must have specific intent that he is washing in order to eat bread, as the Rashba rules. The BI'UR HALACHAH refers to the REMA (OC 158:7) who writes that although the Halachah follows the Rashba, if one did not have specific intent when he washed, he should wash again but without a blessing.