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.
Berean Study Bible (BSB) - 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.”