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:
If - as we know is the case: the indicative. Argument from the less to the greater. If the blood of mere brutes could purify, in however small a degree, how much more shall inward purification, and complete and eternal salvation, be done by the blood of Christ, in whom dwelt all the fullness of the Godhead?
Ashes of an heifer (Numbers 19:16-18). The type is full of comfort. The water of separation, made of the ashes of the red heifer, removed ceremonial defilement whenever incurred by contact with the dead. As she was slain without the camp, so Christ (cf. Hebrews 13:11; Numbers 19:3-4). The ashes were laid by for constant use; so Christ's blood, once for all shed, continually cleanses. In our wilderness journey we are continually defiled by contact with the spiritually dead, and with dead works, and need continual application to the life-giving cleansing blood, whereby we are afresh restored to peace and living communion with God in the heavenly Holy place.
The unclean, х kekoinoomenous (G2840)] - 'those defiled' on any occasion.
Purifying, х katharoteeta (G2514)] - 'purity.'
The flesh - their intrinsic effect extended no further. The law had a carnal and a spiritual aspect: carnal, as an instrument of the Hebrew polity, God, their King, accepting, in minor offences, expiatory victims instead of the sinner, otherwise doomed; spiritual, as the shadow of good things to come (Hebrews 10:1). The spiritual Israelite derived, in these legal rites, spiritual blessings not flowing from them, but from the Antitype. Ceremonial sacrifices released from temporal penalties and ceremonial disqualifications: Christ's sacrifice releases from everlasting penalties (Hebrews 9:12) and moral impurities of conscience disqualifying from access to God (Hebrews 9:14). The purification of the flesh (the outward man) was by "sprinking;" the washing followed by inseparable connection (Numbers 19:19). So justification is followed by renewing.