Looking for chametz
There are two ways of looking at the subject of chametz.
The literal halachic rule says that not even the slightest trace of chametz must be seen or found in a Jewish home on Pesach, so the house has to be thoroughly cleaned and the chametz disposed of.
There is a safety clause in case there still is chametz which one has not seen, found and disposed of; in this case we make a declaration that any such chametz is nullified and deemed to be the dust of the earth.
There is also a metaphorical dimension to the law of chametz. It says: don’t allow in your house or anywhere in your life anything that is questionable. If you know or even suspect it is there, don’t wait to remove it. Don’t be like the theologian who said, “God, make me good – but not yet!”
What chametz symbolises in this spiritual process is arrogance, puffed-up conceit represented by the fact that chametz is a form of leaven that makes the substance rise. If you think too much of yourself, prick your own pomposity.