Num Numbers, chapter Book of Numbers, chapter 18
Therefore thou and thy Banim with thee shall be shomer over your Kehunah with everything of the Mizbe'ach, and within the Parochet; and ye shall do the Avodas service: I have given your Kehunah unto you as an Avodas Mattanah; and the zar (unauthorized one) that shall encroach shall be put to death.Num 3:10; Num 17:5