And he shall sprinkle of the blood upon it with his finger
seven times
This was done with his right finger, or forefinger, as the Targum of Jonathan, and seven times, to denote the perfect cleansing of the altar with it. Jarchi observes, that after he, the high priest, had put the puttings (of blood) upon the horns of it, he sprinkled of it seven sprinklings on the top of it: the Misnah says {u}, upon the pure place of it, that is, upon a place of it, from whence the coals and ashes were removed, and where the gold appeared:
and cleanse it, and hallow it from the uncleanness of the children of
Israel;
by sprinkling the blood upon it; Jarchi's note is, "and cleanse it" from what was past, "and hallow it" for time to come.