+ Positive Mitzvah
Nullify Chometz (leavened food) on the fourteenth of Nissan
“On the first day you shall clear away leaven out of your houses “Shmos 12:15
We know from oral teachings that the first refers to the fourteenth of Nissan before the midday, being the time from when it is forbidden to eat Chometz (leaven food)
Clearing away means that one is to destroy all Chometz that he is aware of in his possession.
That which is unknown he nullifies in his heart and considers it’s as nothing and has no use for it at all.
The Scribes say search, inspect and clear away on the night of the 14th by candlelight because the people are found in their houses at night and the light of the candle is effective for searching.
This applies in all places at all times for men and women.