Leviticus 10:9

7And ye shall not go out from the door of the tabernacle of the congregation, lest ye die: for the anointing oil of the LORD is upon you. And they did according to the word of Moses.

8And the LORD spake unto 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 put 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 unto them by the hand of Moses.