Yoma 73A

תלמוד לומר: ״שבעת ימים ילבשם הכהן תחתיו מבניו אשר יבא אל אהל מועד״, מי שראוי לבא אל אהל מועד. ואם איתא ⁠— מיחזא חזי!

therefore, the verse states: “7 days should he wear them, the one who serves in his stead from among his sons, who comes into the Tent of Meeting to serve in the Sanctuary” (Exodus 29:30). The verse describes a son serving in the place of his father, indicating that the position is inherited. The conclusion of the verse implies that the rule that a son inherits his father’s position applies only to a High Priest who is fit to enter the Tent of Meeting, but not to the priest anointed for war. Based on this baraita, the following challenge is posed: And if it is so, since the priest anointed for war also serves wearing the same garments as the High Priest, he is also fit to enter the Tent of Meeting and should bequeath his position to his son.

אמר רב נחמן בר יצחק, הכי קאמר: כל שעיקר משיחתו לאהל מועד. יצא זה, שעיקר משיחתו למלחמה.

Rav Naḥman bar Yitzḥak said that this is what the baraita is saying: The rule that a son inherits his father’s position applies to anyone for whom the primary purpose of his anointment is to come and serve in the Tent of Meeting. That excludes this priest for whom the primary purpose of his anointment is for war.

מיתיבי: משוח מלחמה אינו משמש לא בארבעה ככהן הדיוט, לא בשמונה ככהן גדול.

The Talmud raises an objection to Rav Dimi’s claim: It was taught in a baraita that the priest anointed for war serves neither in 4 garments, like a common priest, nor in 8 garments, like a High Priest.

אמר ליה אביי: אלא זר משוית ליה! אלא: ככהן גדול ⁠— משום איבה, ככהן הדיוט ⁠— משום מעלין בקדש ולא מורידין.

Abaye said to him: Would you make him like a non-priest? If he dresses like neither a High Priest nor a common priest, then effectively he is like a non-priest, but that is certainly not true. Rather, the meaning of the baraita is that the priest anointed for war does not dress like a High Priest due to the animosity that could be caused between him and the High Priest if they both wore similar garments. Therefore, although according to Torah law the priest anointed for war should dress like a High Priest, the rabbis decreed that he should not, out of concern that animosity might result. And he does not dress like a common priest, due to the principle: One elevates to a higher level in matters of sanctity and one does not downgrade. Since the priest anointed for war attained the level of sanctity of a High Priest, he may not now be demoted to serve as an ordinary priest and dress accordingly.