Sefer Pri Yesha (page 370) relates that the Bais Aharon of Karlin zy”a once said about a certain distinguished young man, “During davening, he follows us step by step. And when it comes time to eat, he becomes a kichel.” His intent was that his avodah of eating was not on the same level as his avodah of davening. He added that the pasuk says (Devarim 2:6): “Ochel tisberu b’kesef” (literally: “you shall buy food from them for money”), which he translated to mean: “One must break (tisberu) his desires for food and the like with ‘kesef’ – with something that a person yearns for (nichsaf).
Similarly, the Magid of Mezheritzh zy”a explains the pasuk of “ochel b’kesef tishbareini” (ibid:28) to mean that if one is “b’kesef”, meaning that he yearns for something like food, he should break this desire.
