Liturgy for Yoma 7:5

ואף לדורות כהן גדול פורש שבעה ומשמש יום אחד ושני תלמידי חכמים מתלמידיו של משה לאפוקי צדוקין מוסרין לו כל שבעה כדי לחנכו בעבודה

i.e., with that mentioned in that section, the section of the Consecration. And what is mentioned in the section about the Consecration? Aaron was removed for seven days and then officiated for one day, and Moses handed over to him<span class="x" onmousemove="('comment',' The eighth day of the Consecration was ministered to by Aaron, Lev. IX, 2.');">¹²</span>

Machzor Rosh Hashanah Ashkenaz Linear

Machzor Yom Kippur Ashkenaz Linear