On daf 2, Rabbi Zeria learns out his thoery that the Sukah must provide shade and if the sukah is 20 amos and above then its posel on the basis tht the shade is coming from walls. He brings his proof from a pasuk in Nach.
On what basis can he bring this as a proof considering we do not learn halacha from nach?
Ben Horne, London, England
The Aruch la'Ner (DH Sukah d'Oraysa) says that according to Rebbi Zeira, the Limud is Halachah l'Moshe mi'Sinai, and the Passuk he quotes is an Asmachta. We find the Gemara says this elsewhere (for example the Aruch la'Ner quotes end of second Perek of Sanhedrin).
He proves this from the fact that the Gemara does not say that Raba and Rava did not want to say like Rebbi Zeira because their reasons are Min ha'Torah and his reason is mi'd'Ra bannan.