Albert Barnes Commentary Leviticus 1:11

"And he shall kill it on the side of the altar northward before Jehovah: and Aaron`s sons, the priests, shall sprinkle its blood upon the altar round about." — Leviticus 1:11 (ASV)

Northward before the Lord - That is, on the north side of the altar. See also (Leviticus 4:24), (Leviticus 4:29), (Leviticus 4:33); (Leviticus 7:2). This was probably an arrangement of some practical convenience. On the west side of the altar stood the laver; on the east side was the place of ashes (see Leviticus 1:16 note); and the south side, where appears to have been the slope by which the priests went up to the altar, must have been left clear for a path.