Leviticus 14:57

To teach when it is unclean. — This verse is intimately connected with Leviticus 14:54, viz.: “This is the law for all manner of plague of leprosy... to afford instruction in the day of uncleanness, and in the day of cleanness:” that is, to furnish them with instructions against the time when they would have to deal with these cases in taking possession of the promised land. The ancient authorities, however, insisted upon the literal rendering which is substantially exhibited in the Margin of the Authorised Version, viz., “To teach concerning the day of uncleanness and concerning the day of cleanness: i.e., to instruct the people on which days this distemper may be examined and decided. Hence the ancient Chaldee Version of Jonathan renders it, “That the priests may teach the people to discern between the dark days, when his leprosy is to be examined, and between the bright days.” (See Leviticus 13:2.)