Midrasz do Kapłańska 9:4

3) (Vayikra 10:12) "Take the meal-offering": This is the meal-offering of Nachshon (viz. Bamidbar 7:12-13). "remaining (from the fire-offerings of the L–rd"): This is the meal-offering of the eighth day (viz. Vayikra 9:4). "from the fire-offerings of the L–rd": They can eat it only after (the sacrifice of) the fire-offerings.

4) (Vayikra 9:4): "and an ox and a ram for peace-offerings": Because their sin was two-faceted, viz.: "They have made themselves a molten calf and (Tehillim 106:20): "And they exchanged their glory for the likeness of an ox eating grass" — let an ox come and atone for the "act" of the ox; let a calf come and atone for the "act" of the calf. Know that the L–rd has been conciliated to atone for your sins. The transgression that you are in fear of lies already slaughtered before the L–rd, viz. (Vayikra, Ibid.) "to slaughter before the L–rd." Israel said before Moses. How can a province praise a king without seeing his face? He responded: Even so, "for today the L–rd will appear to you" (to repose His shechinah in the work of your hands.)

When a man causes a drop of his blood to flow (through circumcision), it is as precious to the Holy One, blessed be He, as the sacrifices. The Holy One, blessed be He, appeared to Abraham after he circumcised himself, just as he did when he offered sacrifices, as it is said: And an ox and a ram for a peace-offering to sacrifice before the Lord…. for today the Lord appeareth unto you (Lev. 9:4).

11) (Vayikra 10:14): "They are given from the sacrifices of the peace-offerings of the children of Israel" — including the communal peace-offerings that obtained that day, as it is written (Vayikra 9:4) "and an ox and a ram for peace-offerings to sacrifice before the L–rd." (Vayikra 10:15): The shok of the lifting and the breast of the waving, on the fire-offerings of the fats shall they bring" — whereby we are taught that the fats were below.

14) (Vayikra 9:1): "And it was on the eighth day": the eighth day of the consecration of Aaron and his sons. — But perhaps the eighth day of the month is being referred to! — (This cannot be, for) it is written (Shemoth 40:17): "And it was in the first month of the second year on the first of the month that the mishkan was set up" — whereby we are taught that the mishkan was set up on Rosh Chodesh (Nissan). I might think that it was set up on Rosh Chodesh and the shechinah reposed upon it on the eighth of the month; it is, therefore, written (Bamidbar 9:15): "And on the day that the mishkan was erected, the cloud covered the mishkan) — whereby we are taught that on the very day that the mishkan was set up the shechinah reposed on the handiwork of Aaron. For all of the (first) seven days of the miluim Moses served (as high-priest) and the shechinah did not repose (there) through him — until Aaron came (on the eighth day) and ministered in the vestments of the high-priesthood and the shechinah reposed (there) through him, as it is written thereof (Vayikra 9:4): "For today the L–rd will appear to you."

[(Ps. 99:6): MOSES AND AARON WERE AMONG HIS PRIESTS, <AND SAMUEL WAS AMONG THOSE WHO CALL UPON HIS NAME>. <Said> R. Judan in the name of R. Jose b. R. Judah <and> R. Berekhyah in the name of R. Joshua bar Qorhah: All those forty years that Israel was in the desert Moses was not prevented from serving in the High Priesthood.¹¹³PRK 4:5; PR 14:11; Lev. R. 11:6; M. Pss. 99:4. This is what is written (in Ps. 99:6): MOSES AND AARON WERE AMONG HIS PRIESTS. R. Berekhyah in the name of R. Simon proved it from here (in I Chron. 23:13–14): THE SONS OF AMRAM: AARON AND MOSES. AARON WAS SEPARATED OUT TO CONSECRATE THE MOST HOLY THINGS, HE AND HIS SONS FOREVER, TO MAKE BURNT OFFERINGS BEFORE THE LORD, <…,> TO PRONOUNCE BLESSINGS IN HIS NAME FOREVER; BUT AS FOR MOSES, THE MAN OF GOD, HIS SONS WERE TO BE NAMED TOGETHER WITH THE TRIBE OF LEVI. Moses is called, THE MAN OF GOD; but as for HIS SONS, it is TOGETHER WITH THE TRIBE OF LEVI that they were to be be named. R. Eleazar b. R. Jose said: It is clear to us that Moses served in a white robe (as High Priest) in the desert.¹¹⁴Above, Gen. 2:20; yYoma 1:1 (38b); Ta‘an. 11b; AZ 34a. R. Tanhum b. R. Judan said: The whole seven days (of the priestly consecration described in Lev. 8) Moses served in the High Priesthood, but the Divine Presence did not rest in his hands; however, when Aaron came and served in the High Priesthood, the Divine Presence did rest in his hands. This is what is written (in Lev. 9:4): FOR TODAY THE LORD IS APPEARING UNTO YOU.