On the evening following the 13th of Nissan (if the first day of Passover is on Sunday, on the evening following the 12th of Nissan) after the evening service, the head of the household makes the final preperation for Passover by searching for leaven throughout the house. It is customary to place a few pieces of bread in various places, so that when the search is make leaven is found. Otherwise the benidiction recited before the ceremony could be in vain.



