Daf Yomi - Sukkah 12 - S'chach Defines a Sukkah

The Gemora states that if one made a sukkah on a movuy that has a lechi, it is valid. The same is true regarding a sukkah by passei biroos. Rashi learns that the sukkah is only valid on Shabbos for then we can apply the principle of migu - since it is deemed a wall regarding Shabbos, it is considered a wall in respect for sukkah as well. The Aruch Lenar asks that this should be considered a sukkah that is not fitting for all seven days and it is ruled on daf 23 that this can invalidate a sukkah?

We offered several answers previously. The Marcheshes based on a Rashi on our daf answers that this halacha is only relevant to the s'chach of the sukkah and not to the walls. The s'chach by itself is fitting for all seven days, it's the walls that are only valid on Shabbos. The Gemora on daf 23 is discussing a case where the sukkah is on an animal and therefore the sukkah will be disqualified for it's not fitting for all seven days for the walls and the s'chach cannot be used on Shabbos.

This is also the explanation for the opinion of the Rosh who rules that one is forbidden to derive any benefit from the s'chach of the sukkah, however he is permitted to have pleasure from the walls. Rashi states that all which is learned from the words chak hasukkos is referring exclusively to the s'chach for the s'chach defines a sukkah, not the walls.