only with regard to teruma that in modern times is sacred by rabbinic law, as the Torah obligation to separate teruma was abrogated after the destruction of the First Temple. However, with regard to leavened bread, which is prohibited by Torah law, do we say that this principle applies? The Talmud responds: Is that to say that the search for leavened bread is required by Torah law? It is a rabbinic ordinance, as by Torah law, mere nullification is sufficient. Since the issue at hand is not the Torah prohibition of leaven but the rabbinic ordinance to search one’s house, this halakha is comparable to the case of baskets of teruma and non-sacred produce.
צבור אחד של חמץ ולפניו שני בתים בדוקין, ואתא עכבר ושקל, ולא ידעינן אי להאי על אי להאי על — היינו שני שבילין. דתנן: שני שבילין, אחד טמא ואחד טהור, והלך באחד מהן ועשה טהרות, ובא חבירו והלך בשני ועשה טהרות.
The Talmud presents another situation: In a case where there is one pile of leavened bread and before it there are two houses that were searched, and a mouse came and took a morsel from the pile, and we do not know if it entered this house or if it entered that house, this is akin to the case of two paths, as we learned in a Mishnah: There were two paths, one of which was ritually impure due to a corpse buried there, and one of which was ritually pure. And someone walked on one of them, but he does not remember which, and afterward he engaged in handling items of ritual purity, e.g., teruma or consecrated items; and another person came and walked on the second path, and he too does not remember which path it was, and he also engaged in handling items of ritual purity.