If you can help me with Pshat on 78B I don't understand the Kasha against Rava he says, one is liable for Neyar Machuk if there is room on the Lavan for two small letters, since there is also room to hold it on the MAchuk!
Pesach Feldman, Jerusalem, Israel
The Kashya on Rava from the Beraisa, which writes that 'ha'Motzi N'yar Machuk ... Im Yesh be'Loven she'Lo, K'dei Lichtov Sh'tei Osi'yos ... Chayav' is - that the paper in this Beraisa does not require a margin in addition to the space containing the erased writing (which will suffice for him to hold it by) in which case 'two letters' must mean two large letters of 'Kesher Muchsin' (to fill up the entire space which was not yet written on).
I didn't understand what is difficult for Rava - a Beraisa can refer to the Shiur as two big letters alone, or two small letters plus a margin, since both of these are the same! Chidushei ha'Ran answers what bothered me - he says that there is a Sevara that all the Tana'im refer to letters of the same size if not specified.