Is one required to search through all his books to ensure that there is no Hametz in them?
People occasionally bring books to the table while they eat bread, bagels, cakes or Hametz snacks, and crumbs frequently fall into the books, in between the pages. Given this possibility, is one required to search through his entire library before Pesah? After all, Halacha requires searching "Kol Makom She’machnisim Bo Hametz" – "all places where one brings Hametz." Seemingly, one’s books are also a "place where one brings Hametz," in which case one must search through all his books, or at least close off his library and sell its Hametz for Pesah.
Indeed, the Hazon Ish (Rabbi Abraham Yeshaya Karelitz, 1879-1954) held that one must go through his entire library before Pesah, page by page, in search of Hametz, and this was his personal practice.
Others, however, including Hacham Ben Sion Abba Shaul (Israel, 1923-1998) and Hacham Ovadia Yosef, disagree. In their view, one is not required to check his books for Hametz, because any Hametz that fell into the books from cake, bread and the like are only "Perurim" – crumbs that are smaller than a Kezayit. While Halacha indeed requires searching all places where he normally brings Hametz, this applies only to places where there may be a Kezayit of Hametz, and not small crumbs. Crumbs that are less than a Kezayit, these authorities maintain, are deemed insignificant with respect to the prohibition against possessing Hametz on Pesah, and one therefore is not required to search through his books. True, some Rishonim (Medieval Halachic authorities) maintain that kneading boards must be cleaned before Pesah and all the small pieces of dough stuck to the boards must be eliminated. However, this is due to the fact that dough is adhesive, and the little pieces are therefore capable of combining with each other to form a Kezayit. This is not the case regarding crumbs of baked foods, and therefore one need not search through his books before Pesah. One who wishes to be stringent in this regard certainly may, but this is not required according to Halacha.
Summary: Although some authorities required checking all one’s books before Pesah for Hametz crumbs, the accepted view is that this is not necessary.
