Leviticus 22:3

Whosoever he be . . . that goeth unto the holy things—The multitude of minute restrictions to which the priests, from accidental defilement, were subjected, by keeping them constantly on their guard lest they should be unfit for the sacred service, tended to preserve in full exercise the feeling of awe and submission to the authority of God. The ideas of sin and duty were awakened in their breasts by every case to which either an interdict or an injunction was applied. But why enact an express statute for priests disqualified by the leprosy or polluting touch of a carcass [Leviticus 22:4], when a general law was already in force which excluded from society all persons in that condition? Because priests might be apt, from familiarity, to trifle with religion, and in committing irregularities or sins, to shelter themselves under the cloak of the sacred office. This law, therefore, was passed, specifying the chief forms of temporary defilement which excluded from the sanctuary, that priests might not deem themselves entitled to greater license than the rest of the people; and that so far from being in any degree exempted from the sanctions of the law, they were under greater obligations, by their priestly station, to observe it in its strict letter and its smallest enactments.