Leviticus 10:8-11

8 ¶ And the Lord spake unto Aaron, saying, 9 Do 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: 10 And that ye may put difference between holy and unholy, and between unclean and clean; 11 And that ye may teach the children of Israel all the statutes which the Lord hath spoken unto them by the hand of Moses.