Menachos Daf 19 מנחוס דַף 19

The Gemara asks that Rebbe Shimon, who darshens a “vav” to add a second subject onto a previously mentioned subject, should require a Kohen for shechitah, since the “vav” introducing Kohanim in the passuk is mentioned after shechitah. It answers that since shechitah is written near סמיכה – leaning on the animal, we derive that just as סמיכה is performed by זרים, shechitah is also valid with a זר. The Gemara asks that we should also derive that just as סמיכה must be performed בבעלים – by the owners of the korban, the owners should also need to shecht their korban!? The Gemara first answers that since זריקה, which is the עיקר כפרה – main cause of atonement, is not performed by the owners, certainly the same should apply to shechitah. If we cannot derive אפשר משאי אפשר – “possible” from “impossible” (i.e., shechitah, which can theoretically be done by the owner, from zerikah, which requires a Kohen), then we can answer that the Torah specified that on Yom Kippur, the Kohen Gadol shechts the bull "אשר לו" – which is his, מכלל דשחיטה בעלמא לא בעינן בעלים – implying that shechitah normally does not need to be done by the owner.

Rav said: כל מקום שהחזיר לך הכתוב בתורה מנחה – wherever the Torah repeated itself to you regarding minchah, אינו אלא לעכב – it is only to teach that the law is essential to the minchah. Shmuel says that only גרש – fine flour and שמן – oil, which are repeated, are מעכב, but other things which are repeated are not מעכב. Since Shmuel surely agrees that repetition of a law teaches that it is מעכב, the Gemara explains that they are arguing about the law derived from the phrases "מלא קומצו" "בקומצו" – “his full hand” and “in his kometz”: שלא יעשה מדה לקומץ – that one may not make a measure for the kometz; rather, one must take kemitzah with his hand. Rav says that this law is מעכב, because during the inauguration of the משכן, it is repeated: ויקרב את המנחה וימלא כפו ממנה – and he brought the minchah near, and he filled his palm from it, indicating it must be taken by hand. Shmuel responds: דורות משעה לא ילפינן – we do not derive permanent laws for generations from laws of a one-time [minchah].

The Gemara asks that two pesukim dictate to bring a minchah close to the מזבח, yet הגשה is not מעכב!? It answers: ההוא לקבוע לה מקום הוא דאתא – that comes to establish the location [of the מזבח] to which the minchah is brought. In a Baraisa, the Tanna Kamma says that "לפני ה'" – before Hashem would indicate the minchah should be brought to מערב – the west side of the מזבח, whereas the phrase "אל פני המזבח" – to the front of the mizbeiach implies דרום – the south side (where the ramp is located). This apparent contradiction leads to the conclusion: מגישה בקרן דרומית מערבית – he brings it to the southwest corner (of the מזבח), כנגד חודה של קרן – to the edge of the corner, ודיו – and that is sufficient. Rebbe Eliezer says that wherever you find two pesukim, one which fulfills itself and fulfills the other, and one which fulfills itself and negates the other, we follow the passuk which fulfills both. Since placing the minchah on the western side would not fulfill “the front of the מזבח,” the Kohen places it on the southern side, which does fulfill “before Hashem” (because he holds the south side of the מזבח was opposite the Heichal entrance).