Leviticus 16:14-15

14He is to take some of the bull’s blood and sprinkle it with his finger against the east side of the mercy seat; then he will sprinkle some of the blood with his finger before the mercy seat seven times.

15“When he slaughters the male goat for the people’s sin offering and brings its blood inside the curtain, he will do the same with its blood as he did with the bull’s blood: He is to sprinkle it against the mercy seat and in front of it.