Exodus 30:10
And Aaron shall make an atonement on 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 on it throughout your generations: it is most holy to the LORD.
Nave's Topical Index—AKJV

Leviticus 4:7,18,25,30
And the priest shall put some of the blood on the horns of the altar of sweet incense before the LORD, which is in the tabernacle of the congregation; and shall pour all the blood of the bullock at the bottom of the altar of the burnt offering, which is at the door of the tabernacle of the congregation.
Nave's Topical Index—AKJV

Leviticus 5:9
And he shall sprinkle of the blood of the sin offering on the side of the altar; and the rest of the blood shall be wrung out at the bottom of the altar: it is a sin offering.
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Leviticus 9:9,12
And the sons of Aaron brought the blood to him: and he dipped his finger in the blood, and put it on the horns of the altar, and poured out the blood at the bottom of the altar:
Nave's Topical Index—AKJV