Hebrews 1:3

He is the reflection of God's glory, and the representation of his being, and bears up the universe by his mighty word. He has effected man's purification from sin, and has taken his seat on high at the right hand of God's Majesty,

Hebrews 9:7

but only the high priest could enter the inner part, and he but once a year, and never without taking some victim's blood, to offer on his own behalf and for the sins committed through ignorance by the people.

Hebrews 9:22-23

In fact, under the Law, almost everything is purified with blood, and unless blood is poured out nothing is forgiven.

Hebrews 9:25

Nor does he go in to offer himself over and over again, like the high priest who enters the sanctuary year after year, taking with him blood that is not his own,

Treasury of Scripture Knowledge

Summary

And Aaron shall make an atonement upon the horns of it once in a year with the blood of the sin offering of atonements: once in the year shall he make atonement upon it throughout your generations: it is most holy unto the LORD.

Bible References

Aaron

Hebrews 1:3
He is the reflection of God's glory, and the representation of his being, and bears up the universe by his mighty word. He has effected man's purification from sin, and has taken his seat on high at the right hand of God's Majesty,
Hebrews 9:7
but only the high priest could enter the inner part, and he but once a year, and never without taking some victim's blood, to offer on his own behalf and for the sins committed through ignorance by the people.