The priests could not cleanse the lepers; but when the Lord removed the plague, various rules were to be observed in admitting them again to the ordinances of God, and the society of his people. They represent many duties and exercises of truly repenting sinners, and the duties of ministers respecting them.
If we apply this to the spiritual leprosy of sin, it intimates that when we withdraw from those who walk disorderly, we must not count them as enemies, but admonish them as brethren. And also that when God by his grace has brought to repentance, they ought with tenderness and joy, and sincere affection, to be received again.
Care should always be taken that sinners may not be encouraged, nor penitents discouraged. If it were found that the leprosy was healed, the priest must declare it with the particular solemnities here described.
The two birds, one killed, and the other dipped in the blood of the bird that was killed, and then let loose, may signify Christ shedding his blood for sinners, and rising and ascending into heaven. The priest having pronounced the leper clean from the disease, he must make himself clean from all remains of it.
Thus those who have comfort of the remission of their sins, must with care and caution cleanse themselves from sins; for every one that has this hope in him, will be concerned to purify himself.