After reassuring Benei Yisrael that God would lead them to victory over the nations of Canaan, Moshe warned them to destroy the Canaanites’ idolatrous articles, and admonishes, “lo tavi to’eiva el beitekha” – they should not bring objects of pagan worship into their homes (7:26).
Chazal interpreted this prohibition both in its literal sense, and as a broader prohibition. On the one hand, the Mishna in Masekhet Avoda Zara (21a) establishes that it is forbidden to lease one’s home as a residence for a pagan, as this would result in objects of idolatrous worship being brought into his home, in violation of “lo tavi to’eiva el beitekha.” This clearly reflects the literal meaning of this prohibition, which forbids allowing idols into one’s home. Additionally, however, the Gemara rules in Masekhet Pesachim (48a) that one violates this prohibition by deriving benefit from an object of pagan worship. The example given is an asheira, a type of tree which was worshipped by an ancient pagan cult. If one uses the wood for his personal benefit, the Gemara teaches, he transgresses the prohibition of “lo tavi to’eiva el beitekha.”
The Avnei Neizer (O.C. 375) explains that the broader interpretation of this law flows naturally from the literal meaning. The Torah forbids bringing an object of pagan worship into one’s home, and Chazal understood that deriving direct, personal benefit from an idol is no different from bringing it into one’s home. By directly benefitting from the idol, one essentially brings it into his life, and, in a sense, even into his very being. Therefore, the prohibition against benefiting from an idol is a natural extension of the prohibition against bringing it into one’s home.
On this basis, the Avnei Neizer suggests explaining the view of the Ran in Masekhet Pesachim. The Gemara (Pesachim 28b) cites the view of Rabbi Shimon, who appears to maintain that there is no Biblical prohibition against benefiting from chametz on Erev Pesach. Whereas Rabbi Yehuda rules that all the chametz prohibitions take effect already in the afternoon of Erev Pesach, Rabbi Shimon – according to the straightforward reading of the Gemara – rules that no Torah prohibition applies before the actual onset of Pesach. The Ran, however, advances a different reading of the Gemara, according to which Rabbi Shimon concedes that the Torah forbids eating and deriving benefit from chametz in the afternoon of Erev Pesach, but he maintains that one who does so is not liable for transgressing a mitzvat lo ta’aseh (a Biblical prohibition). It appears that according to the Ran’s understanding of this view, there is an affirmative command to abstain from chametz already on Erev Pesach, but the Biblical prohibitions against eating and deriving benefit from chametz do not take effect until the evening, when Pesach begins. The question naturally arises as to where the Torah issues such an affirmative command. If the Torah’s prohibition against eating and benefiting from chametz do not apply on Erev Pesach, then on what basis does the Ran say that there is nevertheless a Biblical command to abstain from chametz at this time?
The Avnei Neizer explains that this conclusion stems from the command of “tashbitu se’or mi-bateikhem,” which obligates us to rid our homes of chametz already by the afternoon of Erev Pesach. If the Torah requires banishing chametz from our homes, the Avnei Neizer reasons, then it naturally extends to all forms of personal benefit. As in the case of objects of pagan worship, a requirement to ban chametz from the home ipso facto translates into a ban against personal benefit, whereby one brings the chametz into his life and into his being.