Chrysostomus

I ask myself if there is anyone who can help me.
I remember that I read "somewhere" about a speech of Johanes
Chrysostomus, a speech from 399 AC where he said that the
thracians translated the bible in their language.
This transaltion is supposed to have been made almost in the
same period of time with the translation of Codex Sinaiticus.
Because I do not remember anymore this "somewhere" where I
read, I ask you if you have such kind an information, with a
more precisely source as my "somewhere"...