13 The blood of goats and bulls and the ashes of a heifer sprinkled on those who are ceremonially unclean sanctify them so that they are outwardly clean.

Read Hebrews 9:13 Using Other Translations

For if the blood of bulls and of goats, and the ashes of an heifer sprinkling the unclean, sanctifieth to the purifying of the flesh:
For if the blood of goats and bulls, and the sprinkling of defiled persons with the ashes of a heifer, sanctify for the purification of the flesh,
Under the old system, the blood of goats and bulls and the ashes of a heifer could cleanse people’s bodies from ceremonial impurity.