Study Zevachim folio 79A with parallel Hebrew-English text, traditional commentary, and modern study tools. Free access to Babylonian Talmud online.
Text Excerpt
הא דידיה הא דרביה. דתניא, רבי יהודה אומר משום רבן גמליאל: אין דם מבטל דם, אין רוק מבטל רוק, ואין מי רגלים מבטלין מי רגלים.
this statement, that the water of purification is nullified in a majority of water, is his, i.e., R' Yehuda’s, own opinion, whereas that statement, in the baraita, that white wine is not nullified in a majority of water, is his teacher’s ruling, i.e., that of Rabban Gamliel, who is stringent with regard to a mixture of a substance in contact with the same type of substance. As it is taught in a baraita that R' Yehuda says in the name of Rabban Gamliel: Blood does not nullify blood, spittle does not nullify spittle, and urine does not nullify urine.
Rava says there is a different resolution of the apparent contradiction between the Mishnah that states that water of purification is nullified in a majority of water of a mikveh and R' Yehuda’s opinion in the baraita with regard to white wine mixed with water: In the Mishnah, we are dealing with a bucket whose internal surface is ritually pure, and only its external surface is impure. The significance of this is that by Torah law it suffices for the water of the mikveh to enter the bucket in any amount to purify its external surface, and therefore the water of purification in the bucket does not prevent the purification of the bucket at all.
ורבנן הוא דגזרו בהו דילמא חייס עלייהו ולא מבטיל ליה; וכיון דאיכא ריבויא – לא צריך.
Rava continues: And it is the rabbis who decreed with regard to this case that the internal surface must be purified as well, lest the owner wish to spare the water of purification and not to nullify it from its sanctity. In that case he would wish to avoid allowing water from the mikveh to enter the vessel, and might immerse it in a manner which would not allow even the full external surface to come in contact with the water. Therefore, the rabbis required that one immerse the entire vessel. But once there is a majority of water in the bucket from the mikveh, he does not need to enable any more water to enter the vessel, as by Torah law it is already pure.