Zevachim 156
ונשער מין במינו כמין בשאינו מינו דתנן נתערב ביין רואין אותו כאילו הוא מים מאי לאו רואין אותו ליין כאילו הוא מים
Yet, [where] one kind [is mixed] with its own kind, let us determine [its status] as though it were one kind with a different kind. For we learnt: IF IT WAS MIXED WITH WINE, WE REGARD IT AS THOUGH IT WERE WATER. Does that not mean [that] we regard the wine as though it were water? - No: [it means that] we regard the blood as though it were water. If so, he should state, [The blood] is nullified? Moreover, it was taught, R. Judah said: We regard it as though it were red wine if its appearance goes faint, it is valid; if not, it is invalid! - It is a controversy of Tannaim. <br>
לא רואין אותו לדם כאילו הוא מים אי הכי בטל מיבעי ליה
For it was taught: If one immerses a pail containing white wine or milk, we decide by the excess. R. Judah said: We regard it as though it were red wine: if its appearance goes faint, it is valid; if not, it is invalid. <br>
ועוד תניא ר' יהודה אומר רואין אותו כאילו הוא יין אדום אם דיהה מראהו כשר
But the following contradicts this: If one immersed a pail full of saliva, it is as though he had not immersed it. [If it was full of] urine, we regard it as though it were water. If it was filled with water of lustration, the water [of the mikweh] must exceed the water of lustration. Now, whom do you know to hold [that] we regard'? R. Judah; yet he teaches that an excess is sufficient? - Said Abaye: There is no difficulty:<br>