Mikvaos, Chapter 1, Mishnah 6. This chapter climbs step by step through the grades of gathered water, each level stronger than the one before it. Our mishnah begins with the words "lema'alah meihen," above them: here is a category of water that stands on a higher rung than the waters described in the earlier mishnayos. As we work through the cases, we will see exactly where the difference lies.
The water in question is "mei tamtziyos keshelo pasku": water that collects in the ground and seeps up out of it, at a time when the rain has not yet stopped, while the rainfall is still active and this water is still joined to it. The mishnah now runs through a series of situations that in an ordinary pit would raise a real concern of tumah, and tells us that here none of them present a problem.
The first set of cases: a tamei person drank
Normally, when a tamei person drinks from a pit, we worry about the water that returns from his mouth into the pit. The mishnah therefore addresses three follow-ups:
- "Shasa tamei v'shasa tahor": after the tamei individual drank, a tahor individual came and drank from that same water. His taharah is unaffected.
- "Shasa tamei u'miley bikli tahor": following the drinking of the tamei person, water was drawn out in a vessel that was tahor. Both vessel and contents stay tahor.
- "Shasa tamei v'nafal kikar shel terumah": the tamei person drank, and then a loaf of terumah dropped into the water. The mishnah adds "af al pi shehe'di'ach", meaning that even if he went on to wash that loaf in the water there, so that he lifted water out of the pit willingly and by his own choice, the loaf keeps its taharah.
In every one of these cases the ruling is tahor, because as long as this water is still connected to the stream of falling rain, it is not mekabel tumah at all.
The second set: filling with a tamei kli
The mishnah repeats the same three follow-ups where the opening act was drawing water with a tamei vessel:
- "Miley bikli tamei v'shasa tahor": water was drawn with a vessel carrying tumah, and afterward a tahor person drank from the pit. Nothing has happened to his taharah.
- He drew with the unclean vessel, "miley bikli tamei", and then drew a second time with a vessel that was tahor, "u'miley bikli tahor": the second drawing is tahor as well. The trickle that dribbled back in from the first vessel does not trouble us.
- He drew with a vessel that was tamei, and a loaf of terumah then dropped in, "v'nafal kikar shel terumah". Here too the mishnah states "af al pi shehe'di'ach": even if the loaf was washed off in that water, it stays tahor.
The third set: tamei water fell in
And once more, where actual tamei water fell into this collection of water:
- "Naflu mayim t'meiyim v'shasa tahor": water bearing tumah entered this gathering of water, and a tahor person afterward drank from it. He is unaffected.
- Unclean water entered, "naflu mayim t'meiyim", and water was subsequently drawn with a vessel that carried no tumah, "u'miley bikli tahor": what he drew is tahor.
- Unclean water entered, and then a loaf of terumah dropped in, "v'nafal kikar shel terumah", and once more the mishnah adds "af al pi shehe'di'ach": even where the loaf was washed in that same water, its taharah stands.
The advantage of this grade
These waters carry an additional advantage over the grades listed before them: "kesheirim l'terumah v'litol meihen l'yadayim." They are not merely fit for a dough from which challah will be separated; they are kasher for terumah itself. And naturally one may pour them over his hands for netilas yadayim, and they will not create any difficulty or leave him tamei.
The whole thrust of our mishnah stands in contrast to the earlier mishnayos of the chapter, where we were concerned that a leftover droplet returning into the pit would render everything tamei. Here, since the rain was still coming down and this water is joined to the fresh rainfall, it holds its taharah throughout.
The Bartenura explains why. Recall the standard that Beis Shammai laid down for restoring suspect water to its taharah: "rabu v'shotfu," that fresh rainwater flows in, becomes the majority, and washes the old water over the brim of the pit. Where a tamei droplet had fallen into a pit of otherwise tahor water, that influx would purify it. Our case is essentially the same situation on a permanent basis. Because this water is continuously connected to the rain that is still falling, it is always in the state of rabu v'shotfu, and so it never loses its taharah.