That’s because you’d write it as:

  int a[static 3][4]

You only need to put static on the outermost type, the one that decays into a pointer. Same thing applies if you need restrict:

  int a[static restrict 3][4]

which is ugly but gets the job done. Think of int a[3][4], when used as a function parameter, as “pointer to int[4]” (the 3 disappears completely), and think of int a[static 3][4] as “pointer to first of at least 3 int[4]”.

(Not trying to defend C here, just explaining how C works.)