Reference for Zevachim 159:4
א"ל רבי אליעזר לא נאמר בל תוסיף אלא כשהוא בעצמו א"ל ר' יהושע לא נאמר בל תגרע אלא כשהוא בעצמו ועוד א"ר יהושע כשנתת עברת על בל תוסיף ועשית מעשה בידך כשלא נתת עברת על בל תגרע ולא עשית מעשה בידך:
We learnt elsewhere: In the case of a flask into which a little water fell, R. Eliezer said: He [the priest] makes two sprinklings; but the Sages disqualify [it]. As for the Rabbis, it is well: They hold that we assume even distribution, and sprinkling requires a [minimum] standard, and sprinklings do not combine. But what does R. Eliezer hold? If he holds that there is no even distribution, what if he does sprinkle twice; perhaps he sprinkles [ordinary] water both times? - Rather, he holds that there is even distribution. Now, if he holds that sprinkling does not require a [minimum] standard, why must he sprinkle twice? - Rather, he holds that sprinkling does require a [minimum] standard. And if he holds that sprinklings do not combine, what if he does sprinkle twice? And even if sprinklings do combine, who can say that the standard is made up? - Said Resh Lakish: In truth he holds that there is even distribution, and sprinkling does require a [minimum] standard; but the case we discuss here is where one [standard quantity] was mixed up with another. Raba said: In truth there is even distribution, and sprinkling does not require a standard; but the Rabbis penalised [him] so that he should not benefit thereby. R. Ashi said: There is no even distribution, [therefore] he must sprinkle twice. <br>