Zevachim Daf 51 זבחים דַף 51

A Baraisa discusses the law that לן בדם כשר – if blood stayed past sundown in the עזרה, thereby becoming פסול, is still valid insofar as if it was put on the מזבח (incorrectly), it remains there. This is because לן באימורין כשר – sacrificial parts which remained overnight (become פסול) are valid regarding remaining on the מזבח. This is derived from the fact that לן בבשר כשר – if meat [of a shelamim] stayed overnight, it is fit to be eaten (since a shelamim may be eaten for two days). This law also applies to יוצא – kodashim which left the עזרה, because יוצא is fit for a במה (since it has no enclosure). [It then explains why this law applies to additional פסולים.] The Gemara objects: וכי דנין דבר שלא בהכשירו מדבר שבהכשירו – can we derive the law of something brought improperly onto the מזבח from something done properly?! How can left-over אימורין, which are פסול, be derived from left-over shelamim meat which is permitted? Also, how can יוצא be derived from a במה, which has no restricted area? Therefore, the Gemara explains that this Tanna actually relies on a derashah teaching that some פסולים remain on the מזבח and others do not, and uses the above reasons to determine which ones remain.

In the five פרשיות discussing different kinds of חטאת, the Torah commands pouring the שירים – blood remnants onto the base of the מזבח. Three of them state "אל יסוד מזבח העולה" – onto the base of the mizbeiach “of the עולה” (i.e., the מזבח החיצון). A Baraisa darshens these three superfluous terms: (1) שירים are only poured onto the outer mizbeiach, ולא יסוד מזבח הפנימי – and not onto the base of the inner מזבח (although this korban’s blood was applied on the מזבח הפנימי). (2) אין לו יסוד לפנימי עצמו – there is no base at all on the inner מזבח. (3) תן יסוד למזבח של עולה – give a law of the base for the מזבח of the עולה, meaning that the שירים of עולה and all other korbanos must be poured onto its יסוד. The Baraisa asks that perhaps this last passuk merely teaches that an עולה’s two זריקות must be on a corner of the מזבח with a יסוד underneath (excluding the southeast corner)!? Rebbe Yishmael answers that this is obvious: if שירים, which are not מכפר, require [being poured on] the יסוד, then certainly an עולה’s blood must be נזרק over a יסוד!? Rebbe Akiva says this kal vachomer somewhat differently, and the next Daf analyzes the difference.

The Baraisa darshened the third instance of "אל יסוד מזבח העולה" (written by the שעיר נשיא) to teach that the שירים of all korbanos must be poured on the יסוד of the מזבח החיצון. The Gemara explains that if the passuk were merely teaching where to pour the שירים of the שעיר נשיא, why would this need a passuk? הא בראי עביד להו – But [its avodah] was done on the outer מזבח, so obviously its שירים should also be poured on the מזבח החיצון!? And if you will say דאפיך מיפך דבראי לגואי ודגואי לבראי – that we should switch the outer שירים to the inner מזבח, and the inner שירים to the outer מזבח (i.e., without a passuk one might think that just as the “inner” שירים was poured on the מזבח החיצון, the “outer” שירים of the שעיר נשיא should be poured on the other מזבח, the מזבח הפנימי), but this is impossible, since the Baraisa darshened above that the מזבח הפנימי had no יסוד at all! Therefore, this passuk must instead be teaching that שירים of all korbanos are poured on the יסוד of the מזבח החיצון.