The philosopher Aristotle coined the phrase, "Nature Abhors a Vacuum" after numerous experiments that seemed to illustrate that when all the air is taken out of an object, the pressure inside reduces to nearly zero. As a result, when the object is punctured, higher pressure air around the object rushes in to fill the empty space inside. During the Days of Unleavened Bread, we picture removing the sin from our lives, searching out and looking for every figurative crumb. If we do nothing further, something... anything will fill the holes. It is critical that we take in unleavened bread during the Days of Unleavened Bread, not just remove the leaven, but fill the holes that are left with something good and holy so that when these days are over, the same old habits, and same old sin doesn't find itself entrenched again.