In Sukkah 9a, Rebbi Akiva said the wood of a sukkah is Asur for all seven days. If my chevrusa is correct, tosafos (Aztei sukkah) says that Rebbi Akiva said that only for the wood that is "hechsher sukkah".
What is considered "hechsher sukkah". If the Sukah is only two walls and a tefach ok - it is all Asur. But what about if it has four walls? What is considered the "hechsher sukkah"? How does one know where the hechsher sukkah is?
Elie Samet, Yerushalayim
1) Tosfos (9a, DH Minayin) writes in the name of Rabeinu Tam that only the wood that is enough for "Hechsher Sukah" is forbidden mid'Oraisa, while what is more than "Hechsher Sukah" is forbidden mid'Rabanan.
2) The Ran in Beitzah (17a in the pages of the Rif, DH v'Atzei) writes that Hechsher Sukah means two walls plus a Tefach. However, the Ran adds that the Heter of Hechsher Sukah only applies if one built the minimum Sukah and afterwards added a wall -- then the latter wall does not become forbidden mid'Oraisa. However, if one built all four walls together, they are all Asur equally.
3) The Mishnah Berurah (in Bi'ur Halachah 638:1, DH v'Im) concludes that the Ran in fact also gives this explanation according to the opinion of Rabeinu Tam. If he built the minimum Shi'ur and afterwards added walls, the addition possesses Kedushah only mid'Rabanan, but if he made the four walls in order, then they all possess equal Kedushah.
G'mar Chatimah Tovah,
Dovid Bloom