1. Exposition

Where does the Old Testament explain the twofold task of the high priest?

Hebrews 5:3 (ESV)

3 Because of this he is obligated to offer sacrifice for his own sins just as he does for those of the people.

His task is to sacrifice vicariously for others (Exodus 28:1) and to bring the necessary sacrifices for himself and his family (Leviticus 9:7; Leviticus 16:6, Leviticus 16:17).1