Looking at this disease in a physical point of view, nothing can possibly be more loathsome; and being, so far as man is concerned, totally incurable, it furnishes a most vivid and appalling picture of sin--sin in one's nature, sin in his circumstances, sin in an assembly. What a lesson for the soul in the fact that such a vile and humiliating disease should be used as a type of moral evil, whether in a member of God's assembly, in the circumstances of any member, or in the assembly itself! I. And first, then, as to leprosy in a person; or in other words, the working of moral evil, or of that which might seem to be evil, in any member of the assembly. This is a matter of grave and solemn import--a matter demanding the utmost vigilance and care on the part of all who are concerned in the good of souls and in the glory of God, as involved in the well-being and purity of His assembly as a whole or of each individual member thereof. It is important to see that while the broad principles of leprosy and its cleansing apply in a secondary sense to any sinner, yet in the scripture now before us, the matter is presented in connection with those who were God's recognized people. The person who is here seen as the subject of priestly examination is a member of the assembly of God. It is well to apprehend this. God's assembly must be kept pure, because it is His dwelling-place. No leper can be allowed to remain within the hallowed precincts of Jehovah's habitation. But then, mark the care, the vigilance, the perfect patience, inculcated upon the priest, lest aught that was not leprosy might be treated as such, or lest aught that really was leprosy might be suffered to escape. Many things might appear "in the skin"--the place of manifestation--"like the plague of leprosy," which, upon patient, priestly investigation, would be found to be merely superficial. This was to be carefully attended to. Some blemish might make its appearance upon the surface, which, though demanding the jealous care of the one who had to act for God, was not, in reality, defiling. And yet, that which seemed but a superficial blemish might prove to be something deeper than the skin, something below the surface, something affecting the hidden springs of the constitution. All this claimed the most intense care on the part of the priest. (See ver. 2-11.) Some slight neglect, some trifling oversight, might lead to disastrous consequences. It might lead to the defilement of the assembly, by the presence of a confirmed leper, or to the expulsion, for some superficial blemish, of a genuine member of the Israel of God.