The new Mishna on our daf brings yet another disagreement between Beit Shammai and Beit Hillel on the topic of food preparation on Yom Tov. If a person needs to climb up into a dovecote to bring down doves for food, Beit Shammai forbids moving a ladder from one dovecote to another, although he can shift it from one opening to another in the same dovecote. Beit Hillel permits even moving the ladder for one dovecote to another.
Rav Hanan bar Ami argues that the only disagreement is in public, when Beit Shammai is concerned with marit ayin. He is afraid that people will think that the ladder is being moved to assist in painting the roof – an activity forbidden on Yom Tov – while Beit Hillel is not concerned about that, since the dovecote indicates that the true nature of his activity is a permitted one. Were the dovecote in a private area, where there is no concern that someone will see and draw the wrong conclusion, even Beit Shammai permits moving the ladder.
The Gemara asks: Is that so? But didn’t Rav Yehuda say that Rav said: Wherever the Sages prohibited an action due to the appearance of prohibition [marit ayin], even if one performs the act in his innermost chamber, where no one will see it, it is prohibited.
While our Gemara suggests that the tanna’im differ regarding this position, the Talmud Yerushalmi quotes a series of Mishnayot that clearly distinguish between activities done in public – which are forbidden – and in private – which are permitted, based upon which, the Yerushalmi rejects Rav’s teaching entirely. The Rashba and others suggest that there is room to differentiate between cases where there is suspicion of an act that is truly forbidden (like our case where painting the roof is forbidden on Yom Tov) and cases where people mistakenly think that a given action is forbidden. In the latter cases the Sages forbade performing such an action publicly, but permitted it to be done in private.
The Rambam rules that marit ayin applies even in private, and explains that our Mishna is a unique case where the Sages were lenient in order to encourage joyous celebration of the holiday.