And put it upon the horns of the altar— The altar of burnt-offering is here meant, upon the horns of which it is also enjoined, ch. Exodus 30:10 that an atonement should be made every year. See the note there.
Related Commentaries of Exodus 29:12
Exodus 29:12
12 And thou shalt take of the blood of the bullock, and put it upon the horns of the altar with thy finger, and pour all the blood beside the bottom of the altar.