Containing The Secret Of Man
If a person has not eaten for several days he may die of hunger. When he finally does eat a small bite of bread. it restores his soul. From this we can see that the small bite of food contains within it the secret of man; his G-dly life force.
Comprehension of this fact is what divides tzaddikim and reshaim. Tzaddikim constantly connect themselves to their supernal Source when dealing with any physical item. When a tzaddik eats, he does not do so just to satiate his appetite, he eats to connect himself to his Creator. The rasha, on the other hand, does the opposite.
(Degel Machaneh Ephraim)