Leviticus 9:9

And the sons of Aaron brought the blood unto him
The blood of the calf of the sin offering, which they had received in a basin when it was slain: and he dipped his finger in the blood, and put [it] upon the horns
of the altar;
the four horns of it, as Moses had done at his consecration, which was an example to him, ( Leviticus 8:15 ) . This was typical of the blood of Christ, to which persons may have recourse from the four quarters of the world for atonement and pardon: and poured out the blood at the bottom of the altar;
what remained after he had put what was proper on the horns of it.