Halakhah zu Wajikra 10:7

That the priests not go out from the Temple at the time of the service: That the priests not go out from the Temple at the time of the service, as it stated (Leviticus 10:7), "And from the entrance of the Tent of Meeting you shall not go out, lest you die." And this prevention was repeated likewise with the high priest, and it stated (Leviticus 21:12), "And from the sanctuary he shall not go out." And the language of Sifra, Shemini, Mechilta d'Miluim 42-43 is "'And from the entrance of the Tent of Meeting' - it could be [that they shall not go out] at the time of the service and [also] not at the time of the service. [Hence] we learn to say, 'And from the sanctuary he shall not go out and he will not profane' - [...] it would be said, when he is officiating. [...] 'For the anointing oil of the Lord is upon you' - I only have Aharon and his sons who were anointed with the oil of anointment, if they went out while serving, they would be liable for death; from where [do I know] for all of the priests of the generations? As it is stated, 'for the anointing oil of the Lord is upon you.'"