Rashi on Numbers 19:13/רש"י על במדבר י״ט:י״ג

1במת בנפש [HE WHO TOUCHES] A DEAD BODY OF ANY PERSON — And what dead body is here intended? That of a human being (נפש האדם), the addition of בנפש האדם serving to exclude the person (body) of an animal, so intimating that uncleanness caused by it does not require sprinkling for its removal. Another explanation of בנפש is, that this term refers to a quarter of a log of blood (this being regarded as the minimum quantity necessary for maintaining life in a human being) (Chullin 72a).

2את משכן ה' הוא טמא HE DEFILES THE TABERNACLE OF THE LORD, if he enters the forecourt even though after having immersed himself, but without having been sprinkled on the third and seventh days,

3עוד טמאתו בו HIS UNCLEANNESS IS YET UPON HIM, although he has immersed himself.