Parshat Metzora - purification of the metzorah

The passuk says in this week’s sedrah:

וְצִוָּה הַכֹּהֵן וְשָׁחַט אֶת הַצִּפּוֹר הָאֶחָת אֶל כְּלִי חֶרֶשׂ עַל מַיִם חַיִּים. אֶת הַצִּפֹּר הַחַיָּה יִקַּח אֹתָהּ וְאֶת עֵץ הָאֶרֶז וְאֶת שְׁנִי הַתּוֹלַעַת וְאֶת הָאֵזֹב וְטָבַל אוֹתָם וְאֵת הַצִּפֹּר הַחַיָּה בְּדַם הַצִּפֹּר הַשְּׁחֻטָה עַל הַמַּיִם הַחַיִּים

“The cohen shall command, and he should slaughter one bird into an earthenware bowl onto spring water. He should take the live bird together with the cedar wood, the scarlet thread and the hyssop. He should dip them and the live bird into the blood of the slaughtered bird, which is on the spring water.”

 

How much water?
How much water should be placed in the earthenware bowl? The gemara in Sotah (16b) says;

תנו רבנן שלשה צריכין שיראו …משום רבי ישמעאל אמרו אף דם צפור …הא כיצד מביא מים שדם ציפור ניכר בהן וכמה רביעית

“The chachamim have taught, there are three things that need to be visibly discernible…in the name of Rebbi Yishmoel they said, also the bird’s blood for the metzorah (the blood must be discernible in the water)…He brings water that the blood of the bird will be discernible in. How much is this? [Not more than] a reviis (~150cc).”

 

According to the chachamim, you do not need to be able to see the blood in the water. According to Rebbi Yishmael, you have to be able to see the blood, therefore you cannot use more than a reviis, as otherwise the blood would be too diluted.

Tosafos (d”h mevi mayim) asks, is it really true to say that you cannot see the blood if there is more than a reviis of water?

וא"ת וכי אינו ניכר ביותר מרביעית … י"ל ניכר דקאמר ממשותו של דם ולאו בשינוי מראה דעלמא

“Is the blood really not discernible if you have more water than a reviis? [Tosafos brings a proof that even wine which is less deeply colored than blood is recognisable at a greater dilution.]”

 

Tosafos answers that when Rebbi Yishmael says it has to be discernible, he means that you can see actual blood. [The blood in the water is not mixed up, it is still recognisable as blood.] Simply being able to see that the color of the water has changed is insufficient. Although if there is more than a reviis of water, the water will be colored from the blood, you will not see actual blood in the water.

 

Bitul
Tosafos continues with another question;

…והא הכא דהוה מין שלא במינו והדבר ידוע שהמים מרובין על הדם ואפילו הכי כתיב בדם? וי"ל כיון דממשותו ניכר הרי הוא בעין

“How can the Torah say that you should dip in the water and in the blood? The water and the blood are min beshe’eino mino (they are different types), so once the blood is mixed in the water it will be batel berov (nullified)?”

As soon as we have more water than blood, the water will nullify the blood and it is no longer possible to say that you have dipped in blood? Tosafos answers that since you need the actual blood to be discernible, the blood is whole and therefore cannot be batel. [There is a general rule in bitul that so long as you can discern the issur, you cannot apply the halacha of bitul.]”

Rb Akiva Eiger asks (in the Gilyon Ha’shas);
How can Tosafos answer that the blood is not batel because it is whole? This is only according to the opinion of Rebbi Yishmael who says that you cannot use more than a reviis of water, but the chachamim say that there is no limit to the amount of water. According to them, the blood will be diluted and will only discolor the water. Therefore we remain with the question of Tosafos, that the blood should become batel berov?

The Brisker Rov z”l (Chiddushei Maran Gri”z Halevi - Hilchos Tumas Tzaraas) answers as follows;
According to Tosafos, the machlokess between Rebbi Yishmoel and the chachamim is not only whether or not the blood has to be discernible, rather the machlokess is whether there is a mitzva to dip in blood at all.

• According to Rebbi Yishmoel, the mitzva is to dip in blood and also in water. Because the blood is discernible, it is not batel berov, and when you dip in the mixture you are dipping in both blood and water.
• According to the chachamim, the mitzva is not to dip in water and also in blood. Rather, the mitzvah is to shecht the first bird onto the water, and then to dip the live bird and the three species into water that has had the blood mixed into it. Mixing the blood into the water is a condition of water that is kosher for dipping, it is not a condition in the dipping itself.

Therefore, Tosafos explains that we do not apply bitul because the blood is discernible. This answer only applies according to Rebbi Yishmoel, but the question is not difficult in the first place according to the chachamim because they are of the opinion that there is no mitzva to dip into blood, the mitzva is only to dip into water that has had the blood of the first bird mixed in to it.