(12) He shall purify himself . . . --The verse may be rendered thus: He shall purify himself with it on the third day and on the seventh day; so shall he be clean; but if he purify not himself on the third day and on the seventh day, then he shall not be clean: so the LXX. and Vulg. (See Numbers 19:19.)

Verse 12. - With it. בּו i.e., as the sense clearly demands, with the water of separation.

19:11-22 Why did the law make a corpse a defiling thing? Because death is the wages of sin, which entered into the world by it, and reigns by the power of it. The law could not conquer death, nor abolish it, as the gospel does, by bringing life and immortality to light, and so introducing a better hope. As the ashes of the heifer signified the merit of Christ, so the running water signified the power and grace of the blessed Spirit, who is compared to rivers of living water; and it is by his work that the righteousness of Christ is applied to us for our cleansing. Those who promise themselves benefit by the righteousness of Christ, while they submit not to the grace and influence of the Holy Spirit, do but deceive themselves; we cannot be purified by the ashes, otherwise than in the running water. What use could there be in these appointments, if they do not refer to the doctrines concerning the sacrifice of Christ? But comparing them with the New Testament, the knowledge to be got from them is evident. The true state of fallen man is shown in these institutions. Here we learn the defiling nature of sin, and are warned to avoid evil communications.He shall purify himself with it,.... That is, with the ashes of the water of purification made of them: and this was to be done first

on the third day; from the time of his touching the dead body. Aben Ezra intimates, that there is a secret or mystery in this and the following number seven; it may respect the third day of Christ's resurrection, who, as he shed his blood for the expiation and purification of sinners, so he rose again the third day for the justification of them:

and on the seventh day he shall be clean; which may denote the perfect state, or sabbath of rest, which remains for the people of God, when all Christ's purified and justified ones shall be clear of all sin, and be the spirits of just men made perfect:

but if he purify not himself the third day, then the seventh day he shall not be clean; whoever is not cleansed from his sins by the blood of Christ, shed for the remission of them, and is not justified from them by him that rose from the dead the third day, will never be cleansed in the world to come, or in the eternal sabbath; but it will then be said, "let him that is filthy be filthy still", Revelation 22:11.