Shmuel Alef 2:36

And it shall come to pass, that every one that is left in thine Bais shall come and bow before him to get an agorat kesef (a silver coin) and a kikar lechem (loaf of bread), and shall say, Put me please into one of the Kehunnot (Divisions of the Kehunah), that I may get a piece of lechem to eat.