1.
Jeno Gal asked:
How does the Rambam interpret this rule since he holds that by a Safek Deraissa we go LeKulah Mideraissa. Thank you.
Jeno Gal, Toronto
2.
The Kollel replies:
The Rambam probably learns like Rashi and Tosfos in Sanhedrin (79a, Rashi DH "Lo Tzericha" and Tosfos DH "v'Chol Kavua") that the source of this law is a Gezeiras Ha'Kasuv from the Pasuk, "v'Arav Lo v'Kam Alav" (as implied by the Gemara there). If this is the case, it is not like a regular case of Safek which does not have a Gezeiras ha'Kasuv of its own.
All the best,
Yaakov Montrose