Sheshach: (Jeremiah 25:26) supposed to be equivalent to Babel (Babylon), according to
a secret (cabalistic) mode of writing among the Jews of unknown
antiquity, which consisted in substituting the last letter of the
Hebrew alphabet for the first, the last but one for the second, and
so on. Thus the letters sh, sh, ch become b, b, l, i.e., Babel. This
is supposed to be confirmed by a reference to
(Jeremiah 51:41) where
Sheshach and Babylon are in parallel clauses. There seems to be no
reason to doubt that Babylon is here intended by this name. (See
Streane's Jeremiah, l.c.)