Leviticus 10:8-11

8And the LORD spoke to Aaron, saying, 9Do not drink wine nor strong drink, thou, nor thy sons with thee, when ye go into the tabernacle of the congregation, lest ye die: it shall be a statute for ever throughout your generations: 10And that ye may make a difference between holy and unholy, and between unclean and clean; 11And that ye may teach the children of Israel all the statutes which the LORD hath spoken to them by the hand of Moses.