the Day of Atonement: Atonement Made On for the High Priest
Source: TTT
Leviticus 16:11
When Aaron presents the bull for his sin offering and makes atonement for himself and his household, he is to slaughter the bull for his own sin offering.
Hebrews 9:7
But only the high priest entered the second room, and then only once a year, and never without blood, which he offered for himself and for the sins the people had committed in ignorance.