Jamieson, Fausset & Brown

Sinim--The Arabians and other Asiatics called China Sin, or Tchin; the Chinese had no special name for themselves, but either adopted that of the reigning dynasty or some high-sounding titles. This view of "Sinim" suits the context which requires a people to be meant "from far," and distinct from those "from the north and from the west" [GESENIUS].