Zevachim 33A

מכלל דתרוייהו סבירא להו: טומאה דחויה היא בצבור.

The Talmud comments: It can be derived by inference that both Abaye and Rava hold that impurity is overridden in cases involving the public and is not entirely permitted.

לימא מסייע ליה: כל הסמיכות שהיו שם קורא עליהן אני תכף לסמיכה שחיטה;

The Talmud returns to discussing Ulla’s statement that partial entry of a ritually impure individual is considered entry: Let us say that a baraita (Tosefta, Nega’im 8:10) supports Ulla’s opinion: Concerning all the cases of placing hands that were there in the Temple, I say about them that the principle: Immediately following the placing of hands on the head of an offering is its slaughter, is applied, meaning that these acts must take place uninterruptedly and in the same location.

חוץ מזו שהיתה בשער נקנור, שאין מצורע יכול ליכנס לשם עד שמזין עליו מדם חטאתו ומדם אשמו. ואי אמרת ביאה במקצת לא שמה ביאה ⁠– ליעייל ידיה ולסמוך!

This is so except for this case of a metzora who places hands on his guilt offering, which was done in the threshold of the Nicanor Gate and not in the Temple courtyard where the guilt offering was slaughtered. The reason for this is that a metzora cannot enter the courtyard until they sprinkle from the blood of his sin offering and from the blood of his guilt offering on the altar on his behalf. The Talmud explains the proof: And if you say that partial entry is not considered entry, let him insert his hands and place them on the head of the offering, and the offering should then be slaughtered in that location next to the gate.

אמר רב יוסף: הא מני ⁠– רבי יוסי ברבי יהודה היא, דאמר: מרחק צפון.

Rav Yosef said: There is no proof from here, as in accordance with whose opinion is this baraita? It is in accordance with the opinion of R' Yosei, son of R' Yehuda, who says that the northern side of the courtyard in which it is permitted to slaughter offerings of the most sacred order, which includes a guilt offering, includes only the area to the north of the altar and not the entire northern section of the courtyard. This area is far north of the entrance to the courtyard, i.e., more than 22 cubits away. Consequently, even if the metzora were to insert his hands into the courtyard and place them on the head of his guilt offering, it would not be permitted to slaughter it there.