Leviticus 16:14, 19

And he shall take some of the blood of the bull and sprinkle it with his finger on the front of the mercy seat on the east side, and in front of the mercy seat he shall sprinkle some of the blood with his finger seven times.

And he shall sprinkle some of the blood on it with his finger seven times, and cleanse it and consecrate it from the uncleannesses of the people of Israel.