Paul Wexler
Explorations in Judeo-Slavic Linguistics
p 47, n 201
(discussing interchange of /n/ and /m/ in loans between Hebrew and Slavic)
'... See also OCz Sephyn 'Judges' (late 14th-early 15th c) < He Å¡oft.Ä«m (Schröpfer 1971:358, line 40) vs. B(ela)r(usian) Softim ~ Å oftimÑ (1519) (Skaryna's forewords to 1 Kings and 1 Judges respectively). I have no evidence of the confusion of the two nasals from any Jewish source; nor is it clear yet whether the unetymological n or m became lexicalized.' http://en.wikipedia.org/wiki/Francysk_Skaryna