The red heifer and the redness of the cedar wood and scarlet probably represent blood. Hyssop seems to have been used for cleansing (Psalm 51:7), and the ashes gathered following the burning were considered to be a sin offering (19:9). When mixed with water it was used for purification and was employed for ritual cleansing after a person came in contact with a dead body.
Thought for the day: We don’t have to worry about such things anymore, because of Jesus Christ!
Hebrews 9:13-15 (WEB) “For if the blood of goats and bulls, and the ashes of a heifer sprinkling those who have been defiled, sanctify to the cleanness of the flesh, how much more will the blood of Christ, who through the eternal Spirit offered himself without defect to God, cleanse your conscience from dead works to serve the living God? For this reason he is the mediator of a new covenant, since a death has occurred for the redemption of the transgressions that were under the first covenant, that those who have been called may receive the promise of the eternal inheritance.”