Zevachim Daf 80 זבחים דַף 80

The next Mishnah discusses various blood mixtures of korbanos. If blood of korbanos of the same number of מתנות are mixed, he should do that number of מתנות. If blood requiring מתן ארבע – four-sided application was mixed with blood requiring a single מתנה, Rebbe Eliezer says he should make four מתנות, because if he only makes one, הרי הוא עובר על בל תגרע – he is thereby transgressing “Do not subtract” (by doing fewer than the four necessary for those korbanos). Rebbe Yehoshua says he should only make one מתנה, because if he performs four, הרי הוא עובר על בל תוסיף – he is thereby transgressing “Do not add” on the korbanos requiring one מתנה. Rebbe Eliezer responds that בל תוסיף only applies כשהוא בעצמו – where [the blood] is by itself, and not mixed with other blood. Rebbe Yehoshua counters that the same holds true for בל תגרע, and adds that if he makes four מתנות, transgressing בל תוסיף, עשית מעשה בידך – you have performed an action, whereas the parallel בל תגרע would be passive.

A Mishnah states: צלוחית שנפלו לתוכה מים כל שהו – regarding a flask [of מי חטאת] into which a minute amount of common water fell, Rebbe Eliezer says: יזה שתי הזאות – he should sprinkle the tamei person twice, but the Chochomim invalidate the water, saying it cannot be effectively used for purification. Although the Rabbonon hold יש בילה – there is even blending, and any הזאה invariably contains מי חטאת, they hold הזאה צריכה שיעור – sprinkling requires a minimum amount of מי חטאת, which each mixed sprinkling may not contain. They also hold אין מצטרפין להזאות – multiple sprinklings cannot be combined to constitute the שיעור, so sprinkling numerous times would not help. Rebbe Eliezer’s opinion is explained in three ways. Reish Lakish says he holds יש בילה, and הזאה צריכה שיעור. The case is where only a single measure of common water was mixed in, so by sprinkling twice, he definitely sprinkled the necessary amount of מי חטאת. Rava says he holds יש בילה, and הזאה does not require a שיעור. One sprinkling is therefore sufficient, but the Rabbis decreed a קנס that he should sprinkle a second time, so he should not gain from the added water.

Rav Ashi says Rebbe Eliezer holds אין בילה, but only a minute amount of water fell in, so by sprinkling a second time, he ensures that some מי חטאת was sprinkled. Rav Ashi’s assertion that Rebbe Eliezer holds אין בילה is challenged from a Baraisa about ניתנין למעלה – [bloods] which should be placed above which were mixed with ניתנין למטה. Rebbe Eliezer says: יתן למעלה והתחתונים עלו לו – he should apply the blood above, and the lower bloods also count when he subsequently applies them למטה. If Rebbe Eliezer holds אין בילה, perhaps all the "למעלה" blood was applied למטה, and vice versa!? The Gemara answers that the case is where most of the blood was "למעלה" blood, and he applied more than the volume of "למטה" blood above, thereby ensuring that some "למעלה" blood was placed there. The "למטה" blood, however, was not necessarily applied למטה, and the Baraisa only means that the lower blood counts regarding שירים of the "למעלה" blood. Several more challenges are mounted against Rav Ashi, and Rava will eventually explain that Rebbe Eliezer’s various rulings, including this Baraisa, are discussing where separate כוסות – cups of blood became confused, but if they were mixed together, they cannot be used, because he holds אין בילה.