Leviticus 9:8-10

Amplified Bible

⁸ So Aaron approached the altar and killed the calf as the sin offering, which was designated for himself. ⁹ The sons of Aaron presented the blood to him; he dipped his finger in the blood and put some of it on the horns of the altar, and poured out the rest of the blood at the altar’s base; ¹⁰ but the fat, the kidneys, and the lobe of the liver from the sin offering he offered up in smoke on the altar, just as the Lord had commanded Moses.