Is the "shiur" for zerika a Halacha or just a technical matter?if it's a Halacha, where is this Halacha taken? from the Gemara is a proof that it's a halacha. The gemara wants to say according to R' Eliezer (if he holds Ain Bila), that the case of Mattan 1 B'mattan 4 is talking that we have exactely 5 parts of blood and therefore when the zerika is finished, blood for each korban reached the Mizbeach.The Gemara asks on this, if so why is there Bal Tosiff according to R' Yehoshua? If one would say, that the shiur for zerika is only a practical matter, then there would be no question; since R Yehoshua holds yesh bila,comes out thet with the zerika rishona he was mekayem Mitzvas zerika for the Mattan 1 and regarding mattan 1 the additional zerikos ar bal tosiph.
yakov finkelstein, toronto canada
I think you are correct that the shiur for Zerika (at least according to many opinions) is a Halachah. This is also apparent from the opinion of Rashi (Zevachim 93b, DH "Kee'bel") that doing Kabalah to less than the amount required for Zerikah in one vessel is Pasul, even if one did Kabalah to the same amout of blood in another vessel as well and proceeded to mix the two together. If everything depended on a "technical amount," than there should be no problem with a Kabalah of less than the required amount in two separate vessels (see also Kiryas Sefer Hilchos Masei ha'Korbanos ch. 4).
Kol Tuv,
Yaakov Montrose