Midrash su Levitico 8:14

12) (Vayikra 8:14): ("And he presented the bullock of the sin-offering, and Aaron and his sons placed their hands on the head of the bullock of the sin-offering.") "And he presented the bullock of the sin-offering": In the beginning, it was not called "the bullock of the sin-offering," viz. (Shemoth 29:1): "And this is the thing that you shall do to them to sanctify them to minister unto Me: Take one young bullock and rams, etc." In its specific accounting it is called "the bullock of the sin-offering," viz. (Shemoth 29:14): "And the flesh of the bullock and its hide and its waste you shall burn in a fire outside the camp — it is a sin-offering." We do not know whether this refers to the sin-offering of Aaron and his sons or to the communal sin-offering. "Take Aaron and his sons with him … and the bullock of the sin-offering" (Vayikra 8:2) tells us that it is the sin-offering of Aaron and his sons and not the communal sin-offering.

13) "and Aaron and his sons placed their hands on the head of the bullock of the sin-offering.": We find that Aaron and his sons perform semichah (the placing of the hands) on all of their offerings. But because they do so because they are their offerings, the offerings of partners are compared to their offerings, viz.: Just as their offerings require semichah for each of the participants, so the offerings of partners require semichah for each partner.

(Lev. 22:29:) AND WHEN YOU SACRIFICE AN OFFERING OF THANKSGIVING TO THE LORD. R. Pinhas, R. Levi, and R. Johanan said in the name of R. Menahem of Galilee: In the age to come all < other > offerings shall cease, but the sacrifice of thanksgiving shall not [ever] cease.⁸³Tanh., Lev. 8:14; Lev. R. 27:12; PRK 9:12; M. Pss. 56:4. All prayers shall cease, but the prayer of thanksgiving shall not [ever] cease. Thus it is stated (in Jer. 33:11): THE SOUND OF JOY AND THE SOUND OF GLADNESS, THE VOICE OF THE BRIDEGROOM AND THE VOICE OF THE BRIDE, THE VOICE OF THOSE WHO SAY: GIVE THANKS TO THE LORD [OF HOSTS, FOR THE LORD IS GOOD,] FOR HIS MERCY ENDURES FOREVER! [AS THEY BRING THANKSGIVING TO THE HOUSE OF THE LORD. (Ibid.:) GIVE THANKS TO THE LORD. This refers to the prayers. AS THEY BRING THANKSGIVING. This refers to the sacrifice of thanksgiving. And so David said (in Ps. 56:13 [12]): YOUR VOWS, O GOD, ARE UPON ME; I WILL REPAY YOU WITH THANKSGIVINGS. "Thanksgiving" (in the singular) is not written here, but THANKSGIVINGS (in the plural), < i.e., both > the thanksgiving prayer and the sacrifice of thanksgiving.