Yoma 13A

הלכה כרבי יוסי, ומודה רבי יוסי שאם עבר ועבד ⁠— עבודתו כשרה. אמר רב יהודה אמר רב: הלכה כרבי יוסי, ומודה רבי יוסי שאם מת ראשון, שחוזר לעבודתו.

The halakha is in accordance with the opinion of R' Yosei that the original High Priest returns to his service, while the second is fit to serve neither as High Priest nor as a common priest. And R' Yosei concedes that if the second priest violated this provision and served as High Priest wearing 8 garments, his service is valid. Rav Yehuda said that Rav said: The halakha is in accordance with the opinion of R' Yosei, and R' Yosei conceded that if the original High Priest dies, the second returns to his service as High Priest.

פשיטא! מהו דתימא, הויא ליה צרה מחיים. קא משמע לן.

The Talmud asks: That is obvious. Clearly, the second priest may serve as High Priest after the first one dies without concern that their rivalry will generate hatred between them. The Talmud answers: Lest you say that the mere knowledge that another priest is in waiting to replace him is enough to generate hatred, and would be for him like a woman whose husband has taken a rival wife in her lifetime; therefore, Rav teaches us that this is not a concern.

רבי יהודה אומר: אף אשה אחרת מתקינין לו. ורבנן נמי, הא חיישי לשמא? אמרי לך רבנן: טומאה שכיחא, מיתה לא שכיחא.

§ It was taught in the Mishnah that R' Yehuda says: The rabbis would even designate another wife for the High Priest lest his wife die. The Rabbis say: There is no concern lest his wife die, and therefore the rabbis did not designate another wife for him. The Talmud asks with regard to the Rabbis: Aren’t they concerned lest he become impure, which is why the rabbis designate a replacement High Priest? Why then, are they not concerned lest his wife die? The Talmud answers that the Rabbis could have said to you: Impurity is common, as it is not unusual for the High Priest to become impure either due to secretions from his body or from an external source. Death is not common, and therefore there is no concern lest his wife die.