Leviticus 4:7-8

7The priest shall also put some of the blood on the horns of the altar of fragrant incense which is before the Lord in the Tent of Meeting. All the rest of the blood of the bull he shall pour out at the base of the altar of the burnt offering which is at the doorway of the Tent of Meeting.

8He shall remove all the fat from the bull of the sin offering—the fat that covers the entrails, and all the fat which is on the entrails,