(ט)
1. מים מלוחים או סרוחים או מרים שאין הכלב יכול לשתות מהם פסולים לנטילת ידים אע"פ שכשרים למי מקוה לטבילה.
2. ואם הם עכורים מחמת טיט שנתערב בהם אם הכלב יכול לשתות מהם כשרים בין לנטילת ידים בין למקוה ואם אינו יכול לשתות מהם פסולים לשניהם:
Introduction:
The main difference between these two cases is this: Even if water is very salty, smelly, or bitter, it is still water. Therefore, even if it becomes passul for netilas yadayim, that's because Chazal put a limit as to the fitness of water for washing. But for a mikvah, as long as you are going into a body of water - it is a good tevilah, and therefore no matter how smelly and not fit even for a dog to drink, since it is at the end of the day "water" it will still work for tevila.
But water that has been mixed significantly with dirt, depending on how much is mixed in can potentially make it not "body of water", rather a "mud bath", and therefore it would be passul for both kinds of washings, because this isn't "water."
(Based on shiur from R' Thaler)
This seif talks about:
1. The pesul of Salty, Smelly, and Bitter Water
2. The pesul of Muddy Water
1. The pesul of Salty, Smelly, and Bitter Water
(ג) הַמַּיִם שֶׁנִּפְסְלוּ מִשְּׁתִיַּת הַבְּהֵמָה, בְּכֵלִים, פְּסוּלִים. וּבְקַרְקָעוֹת, כְּשֵׁרִים...
(3) Water which had become so unfit that it could not be drunk by a beast: If it was in a vessel it is invalid, But if it was in the ground it is valid...
(א) שנפסלו משתיית הבהמה. כגון מחמת סרחון. אבל שנפסלו מחמת טיט, אפילו בקרקע פסולים:
(ב) בכלים פסולים. דלא תקון רבנן נטילה אלא בראויין לשתיית בהמה:
(ג) בקרקע כשרים. להטביל הידים דהא מקוה נינהו וכל גופו טובל בהן, ידיו לא כל שכן:
(1) שנפסלו משתיית בהמה - as for example, on account of offensive smell/stench. But if it became unfit on account of plaster/mud/clay, even in the ground, it is unfit.
(2) בכלים פסולים – for the Rabbis did not establish pouring [water on the hands] other than with what appropriate for animals to drink.
(3) בקרקע כשרים – to ritually immerse the hands for purification, for they are a Mikveh and one immerses in them all of his body, his hands is it not all the more so?
2. The pesul of Muddy Water
אמר ריש לקיש כל המשלים למי מקוה משלים למי כיור לרביעית אינו משלים.
למעוטי מאי אילימא למעוטי טיט הנדוק היכי דמי אי דפרה שוחה ושותה ממנו אפי' לרביעית נמי ואי אין פרה שוחה ושותה ממנו אפילו למקוה נמי אין משלים?
§ Reish Lakish says: Any liquid that may be used to complete the requisite measure of water for a ritual bath may complete the requisite measure of water for the Basin. But it may not complete the quarter-log required for ritual washing of the hands.
The Gemara asks: This statement means to exclude what as unfit for completing the requisite measure for ritual washing of the hands? If we say that it means to exclude liquefied clay, there is a difficulty, as what is this clay like? If it is such that a cow can kneel and drink from it, it is considered water and should be fit even to complete the measure of a quarter-log for ritual washing of the hands. And if a cow cannot kneel and drink from it, it should not even be fit to complete the requisite measure for a ritual bath?
The two pronged question of the Gemara is presented as two cases in the Shulchan Aruch.
If mud is fluid enough for a cow to drink from it, it is considered just like water.
And if the mud is so thick that a cow cannot drink this mud mixture, it cannot be deemed as water at al for any purpose.
Biur Halacha makes the point that, which is a haara only one who looked into the mekor can make:
The Gemara in Zevachim is discussing a cow's tolerance to this mud/water mixture, whereas the Shulchan Aruch says that the barometer of the validity of the water is dependent on a dog's tolerance to drinking the water?
Biur Halacha says that a cow's tolerance is lower than a dog's. In other words, what a dog might eat a cow might not eat, so according to the Gemara in Zevachim, there is an added chumra as to which waters will be valid for netilas yadayim.
He ends off tzarich iyun.