Talmud: According to the Mishnah, a bird sin offering that one sacrificed according to the procedure of a burnt offering is disqualified. The Talmud asks: With regard to what rite did the priest change the procedure? If we say that he changed the pinching by severing the head completely, as is proper for a burnt offering, should we say that the Mishnah is not in accordance with the opinion of R' Elazar, son of R' Shimon, who says: I heard that the priests would sever the head completely even in the sacrifice of a bird sin offering?
ולא אוקימנא דלא כרבי אלעזר ברבי שמעון?!
The Talmud responds: And what is wrong with this conclusion? Have we not already explained that the Mishnah in the previous chapter (65a), with regard to pinching, is not in accordance with the opinion of R' Elazar, son of R' Shimon?
לא; דשני בהזאה.
The Talmud offers another explanation: No, the Mishnah is referring to a case where the priest changed the procedure in the rite of sprinkling by squeezing out all the blood at once, as one would do with a burnt offering, rather than first sprinkling the blood on the altar as is proper for a sin offering. Under such circumstances, R' Elazar, son of R' Shimon, would also agree that the offering is disqualified.
הכי נמי מסתברא – מדקתני סיפא: עשאה למעלה כמעשה כולן – פסולה, ואפילו כמעשה חטאת לשם חטאת. דשני במאי? אילימא דשני במליקה, האמר מר: מליקה בכל מקום במזבח – כשירה! אלא לאו דשני בהזאה? ומדסיפא בהזאה, רישא נמי בהזאה.
This, too, stands to reason that the Mishnah is referring to a change in the sprinkling. This can be inferred from the fact that the Mishnah teaches in the latter clause: If one sacrificed a bird sin offering above the red line according to the procedure of any of the offerings, it is disqualified, and this applies even if he sacrificed it according to the procedure of a sin offering and for the sake of a sin offering. With regard to what rite did the priest change the location of the procedure? If we say that he changed the pinching, performing it above the red line, didn’t the Master already say with regard to a bird sin offering that pinching is valid anywhere on the altar? Rather, is it not that he changed the location of the sprinkling? And since the ruling of the latter clause is stated with regard to sprinkling, by inference, the ruling of the first clause is also stated with regard to sprinkling.