Charles Ellicott Commentary Leviticus 16:19

"And he shall sprinkle of the blood upon it with his finger seven times, and cleanse it, and hallow it from the uncleannesses of the children of Israel." — Leviticus 16:19 (ASV)

And he shall sprinkle. —He then sprinkled with his right finger, seven times, the middle or top of the altar, the coals and ashes having been previously removed so effectually, that the gold appeared. The remainder of the blood he poured out at the western and south-eastern side of the altar, where a drain communicated with the Kidron, to which it was conducted by a pipe.