פירוש על ויקרא 8:28

ויקטר המזבחה [AND MOSES TOOK THEM FROM OFF THEIR HANDS] AND CAUSED THEM TO ASCEND IN FUMES AT THE ALTAR — Moses (though a non-priest) was officiating during the seven days of installation [in a white garment] (Avodah Zarah 34a).

על העולה, upon the burnt-offering. These words mean that nothing else intervened. Perhaps the meaning is that Moses did not wait with accepting the meal-offering from the hands of the priests until the burning up of the burnt-offering had been completed.

Moshe performed [the Temple service] all seven. Re’m writes: I do not know why Rashi explains this here and not on (v. 15): “and Moshe took the blood...” where it would imply all the services that followed afterward were performed by Moshe. Perhaps the answer is: Rashi waited until the end of Moshe’s service. Additionally, we can say: Rashi is answering the question: Why did they burn the thigh on the altar? We do not find any thigh of a peaceoffering that was burnt, as Rashi writes nearby. And Rashi answers: “Moshe performed...” Regarding the breast and the thigh it is written that it shall be to Aharon and his sons as a portion (7:33, 34). For this reason Moshe burnt the thigh on the altar and it was not given to him as a portion, and only the breast [was given to him] to distinguish between him and Aharon and his sons, for they were the kohanim, and he was a Levi. He served only during the seven days of installation. Hashem made this distinction between Moshe and the kohanim, the sons of Aharon. Rashi did not write this above because there it was not necessary to say that Moshe served the entire seven days of installation. Rather, [one could say that] he served only on the first day to teach Aharon the details of service. The rest of the days, however, if they wished, Moshe could bring [sacrifices] to be burnt, or someone else, as long as he knew how to bring them [upon the altar] to be burnt. However, it is written here (v. 25-28): “He took the fat and the fat tail... He put them all on Aharon’s palms and on the palms of his sons and he waved... Moshe took them from their palms and he burned them on the altar in addition to the burnt-offering,” and this raises a difficulty: Why did Moshe perform all these services alone? Rashi explained (7:30) that waving requires three kohanim because the glory of the king is with a multitude of people! Therefore, perforce, no one else was fit to serve besides Moshe. Thus, one must say that Moshe served the entire seven days of installation (Gur Aryeh).

על העולה, “with the burnt offering.”

על העלה [AND MOSES … CAUSED THEM TO ASCEND IN FUMES] על העלה — after the burnt offering (על is taken in the sense of besides, in addition to the burnt offering. Hence he burnt it after the burnt offering). We do not find in any passage, that the shoulder of peace-offerings was burnt except in the case of this alone (cf. Rashi on Exodus 29:22).

After the burnt-offering. It does not literally mean על (upon), for he already burnt the burnt-offering before the slaughtering of this ram.