15a (R. Zeira): If a Kohen was sprinkling and he became blemished before the blood reached the airspace of the Mizbeach, it is Pasul. We require "v'Hizah... v'Nasan." (The Haza'ah is completed when the blood reaches the Mizbeach.)

52b (Mishnah): The blood of (outer) Chata'os of the Tzibur or of a commoner must be put on each of the four Keranos. The Kohen ascends the ramp and walks on the Sovev (the walkway around the Mizbe'ach half-way up the Mizbe'ach), putting on each Keren when he comes to it, i.e. southeast, northeast, northwest and southwest;

He pours the Shirayim on the Yesod in the south;

Question: How is blood put on a Keren?

Answer #1 (R. Yochanan or R. Elazar): He puts blood on one of the (two) outer faces of the Keren, i.e. within an Amah of the edge;

Answer #2 (The other of R. Yochanan and R. Elazar): He puts it along the edge from the top down (until the Sovev).

R. Elazar b'Rebbi Shimon says that blood is put only on the Keren itself. Clearly, this is like Answer #1;

Rebbi permits putting blood below the Keren, as long as it is above the Sovev. This could be like either answer;

Answer #1 allows putting the blood within an Amah of the edge (this is considered like the Keren). Rebbi could permit this even below the Keren. Answer #2 requires putting the blood of the edge, for only the edge is called 'Keren'.

Question (against Answer #1 - Beraisa): To do Matanos Dam of (outer) Chata'os of the Tzibur or of a commoner, the Kohen ascends the ramp and walks on the Sovev to the southeast Keren;

He immerses his right finger, i.e. his skilled finger, in the blood in the bucket, and uses his thumb and pinky to constrict the blood so all will go on the edge, until all the blood from his finger is finished. He does the same on every Keren.

Answer: The first opinion permits putting the blood within an Amah of the edge. He admits that it is best to put it on the edge.

Rambam (Hilchos Ma'aseh ha'Korbanos 5:7): The blood of Chata'os that are eaten must be put four times, (once) on each of the four Keranos of the outer Mizbe'ach. It is put on the top half, for it says "Al Karnos ha'Mizbe'ach." The Kohen takes the blood in a bucket to the Mizbe'ach, immerses his right index finger in the blood in the bucket, and supports it with his thumb and middle finger, and runs his fingers down even with the edge, until he finishes all the blood on his finger. He does the same on every Keren.

Ri Korkus: He uses the most skilled finger for all Melachah and to immerse, i.e. the right index finger. Our text says that he uses his thumb and pinky to constrict the blood so all will go on the edge. The Rambam's text says that he uses his thumb and middle finger. Surely this is correct, for the middle finger is next to the index finger. Rashi says that he draws the blood down, so all will go on the Mizbe'ach. The Rambam says he supports it. Perhaps he means that he holds it gathered in place, so it will not spread on his finger.

Kesef Mishneh: The Rambam's text said 'big finger', unlike our text which says 'small finger.' Alternatively, it is small (in width) compared to the thumb.

Radvaz: The Rambam holds that the other fingers support the index finger and enable it to be straight and firm. Try it! You will see that it needs the other fingers to support it.

Likutei Halachos (53a Zevach Todah DH Amah): Rashi and the Rambam connote that it suffices to put on one side of the Keren. E.g. the blood on two corners could be on the west, and the blood on the others could be on the east. This is difficult, for also regarding blood on the Keranos it says "Saviv", so we should require on all four walls! The two Zerikos of Olah must go on both sides of the edge, in order that there will be blood on all four walls! Perhaps indeed, one may put blood on only one side of the Keren, but then he must out on the others in such a way that there will be blood on all three walls. This requires investigation.

Chazon Ish (Yoma 126:38 DH u'Mechatei): The Beraisa says 'he is Mechatei v'Yored.' Rashi explains that he pulls his finger along the edge. If so, there is no Haza'ah (sprinkling) on the Keranos. There is only Nesinah (putting). Regarding the Keranos, the Torah mentioned only Nesinah, but not Haza'ah. Tevilah and Haza'ah of Dam Chatas is only for inner Chata'os towards the Paroches or on the inner Mizbe'ach. However, the Rambam says that he sprinkles on the Keranos. In Hilchos Yom Kipur he explains 'from above to below' to mean that his hand is above and he sprinkles so that the blood will go below. 'From below to above' means that his hand is below and he sprinkles above. Here, he says 'Mechatei v'Yored', like the Beraisa. It seems that for inner Chata'os, all of the blood is sprinkled, but outer Chata'os is only put. Putting does not suffice even b'Di'eved when sprinkling is required. However, sprinkling suffices when the Mitzvah is Nesinah. Perhaps even l'Chatchilah he may sprinkle if he wants! Zevachim 15a discusses Haza'ah on the outer Mizbe'ach. This is difficult for Rashi, who says that he puts the blood! Perhaps this is after Haza'ah. This is not called adding Haza'os, rather, adding to the Haza'ah. This requires investigation.

Rambam (ibid): If he put the blood within an Amah of the edge on either side, he atoned.

Ri Korkus: Even though the Gemara did not resolve which Amora holds that he atoned if the blood was within an Amah of the edge, the Rambam rules that he atoned, for the Gemara concludes like this. Also, even if it were a Safek, we should not bring (a second Korban due to Safek, for if he already atoned, the latter is) Chulin b'Azarah. He rules like Rebbi, that the primary Mitzvah is to put on the edge. The Halachah follows Rebbi against a colleague, and especially here, for Amora'im argue according to Rebbi.

Kesef Mishneh: The Rambam rules like the Amora who holds that the blood is put within an Amah of the edge. I explain that since R. Elazar b'Rebbi Shimon does not require the edge, it is best to say that also Rebbi does not, to minimize the argument. Also, since Amora'im argue about this, we cannot disqualify (b'Di'eved) if it is within an Amah of the edge. L'Chatchilah, we require on the edge.

Keren Orah (53a DH Aliba): Rashi connotes that on the Keren itself, even l'Chatchilah one need not put on the edge. The edge is required only below. The Rambam said Stam that the Mitzvah is to put on the edge. This connotes even when putting on the Keren itself. He can explain that when it says in the conclusion 'the Mitzvah is to put on the edge', this is even according to R. Elazar. We need not say like the Kesef Mishneh that the Rambam was unsure.

Chak Nasan (53a DH Hachi): The Gemara connotes that Rebbi and R. Elazar argue only about b'Di'eved, but all agree that l'Chatchilah one must put on the edge. The Rambam does not say so due to Safek.

Likutei Halachos (53a Zevach Todah DH Mitzvah): The Gemara and Rambam connote that l'Chatchilah, Rebbi permits to put below the Keren, since it is above the Chut ha'Sikra. I am unsure about the following. He holds that since below the Keren is like the Keren, the place of the Keren is considered to be until four Amos below, but even so, l'Chatchilah the Mitzvah is to put on the edge. Does he say the same when putting on the actual Keren? Perhaps the same applies to R. Elazar. The Gemara initially said that all agree according to R. Elazar (that within an Amah is Kosher), i.e. b'Di'eved, but l'Chatchilah he requires the edge. Or, perhaps anywhere on the Keren itself is called Keren, and it is l'Chatchilah. Rashi connotes like this. However, Rashi (10b DH ul'Ta'amech) connotes like the first way I suggested. The Rambam did not distinguish putting on the Keren itself from putting below. This suggests like my first approach.