Midrash su Levitico 1:11

1) (Vayikra 1:3-4): "… before the L–rd. And he shall place (his hand on the head of the olah"): There is no semichah on a bamah (a temporary altar, it not being considered " before the L–rd"). (Vayikra 1:11): ("And he shall slaughter it on the side of the altar) northward (tzafonah), before the L–rd": There is no tzafon (requirement) on a bamah. Now which measure is greater? That of tzafon or that of semichah? The measure of tzafon is greater. For tzafon obtains both with individual and with communal offerings, whereas semichah obtains only with individual offerings. If I exclude them (bamoth) from tzafon, the greater measure, would I not exclude them from semichah, the lesser measure? (Why, then, is the exclusion verse for bamoth re semichah necessary) Perceived thus, tzafon is the greater measure, and semichah, the lesser. But perceived otherwise, semichah is the greater measure and tzafon the lesser. For semichah obtains with both higher and lower-order offerings, whereas tzafon obtains only with higher-order offerings. If I exclude them (bamoth) from tzafon, the lesser measure, I would not exclude them from semichah, the greater measure. So that because there obtains with tzafon what does not obtain with semichah, and with semichah, what does not obtain with tzafon; it is, therefore, written: "before the L–rd, vesamach" — there is no semichah on a bamah. "tzafonah before the L–rd" — there is no tzafon on a bamah. "before the L–rd vesamach": Even if he performed semichah outside (the azarah), he must return and perform it inside ("before the L–rd").

1) "northward before the L–rd": The north must be empty (so that it is "before the L–rd.") These are the words of R. Eliezer b. Yaakov. The altar was aligned with half the opening of the heichal (the sanctuary), and opposite one of the doors, extending south. R. Yehudah says: The altar was in the mid-point of the azarah, thirty-two amoth — ten amoth opposite the entrance of the heichal, eleven amoth to the north, and eleven amoth to the south. So that the altar is found to be aligned with the sanctuary and its walls.

2) Which is "north" (for purposes of shechitah of higher-order offerings)? From the northern wall of the altar until the northern wall of the azarah, and opposite (the length of) the altar (from east to west). These are the words of R. Yossi b. R. Yehudah. R. Elazar b. R. Shimon adds: to the west (of the altar) between the ulam (the entrance hall to the heichal) and the altar, until the northern wall of the azarah. Rebbi adds: to the north-east (of the altar), the pathway of the Cohanim, and (continuing northward), the pathway of the Israelites, until the northern wall of the azarah. But all agree that (shechitah) is pasul in front (i.e., to the north) of the "cell of knives" (beth hachalafoth, in the north of the ulam [the altar being obscured from there]).