What is "Tzivah Hashem la'Asos le'Chaper Aleichem" referring to?
Rashi #1: It refers to the remaining six days of the Shiv'as Yemei Milu'im.
Rashi #2 (citing Yoma, 2b) and Targum Yonasan 1 : With reference to the seven days that Aharon and his sons had to remain at the entrance of the Ohel Mo'ed, we learn from ("La'asos" that the Kohen who prepared the Parah Adumah, and from "Lechaper" that the Kohen Gadol on Yom Kipur, are obligated to separate from the people, to spend seven days in the Mishkan or in the Beis-ha'Mikdash.
Targum Yonasan: With reference to the seven days that Aharon and his sons had to remain at the entrance of the Ohel Mo'ed, the Pasuk is explaining that it is in order to watch Moshe performing the Avodah - since, following the days of Milu'im, they would have to follow the same procedure, in order to gain atonement on behalf of K'lal Yisrael. 2