Blood of Legal Sacrifices for Atonement
Source: TTT
Exodus 30:10
Once a year Aaron shall make atonement on the horns of the altar. Throughout your generations he shall make atonement on it annually with the blood of the sin offering of atonement. The altar is most holy to the LORD.”
Leviticus 17:11
For the life of the flesh is in the blood, and I have given it to you to make atonement for your souls upon the altar; for it is the blood that makes atonement for the soul.