Whoever touches a dead body, the body of a human being who dies, and does not purify himself, defiles the Mishkan of the Lord, and that person shall be cut off from Yisrael; because the water of sprinkling was not thrown upon him, he shall be unclean; his uncleanness is still upon him.
Torah Temimah: Nazir 45a — “He shall be unclean” — to include a tevul yom; “his uncleanness is still upon him” — to include one who lacks atonement (mechusar kippurim).
English: “He shall be unclean” — to include a tevul yom; “his uncleanness is still upon him” — to include one who lacks atonement (mechusar kippurim).
Inclusion of intermediate impurity statuses.
Even a tevul yom (one who has immersed but whose day has not yet ended) and a mechusar kippurim (one who still needs to bring his atonement offering) are included in the prohibition and penalty of entering the sanctuary while impure.