//http://pastebin.com/NMBR17nR
procedure TForm6.BitBtn1Click(Sender: TObject);
begin
  with TIB_Cursor.Create(nil) do //Criando o Cursor
    begin
      try
        IB_Connection := Conexao;
        SQL.Text      := 'select first 2 * from usuarios order by id';
        Open; //Aqui o SQL aparece na tabela MON$STATEMENTS do firebird
        while (not eof) do
          begin
            ShowMessage(FieldByName('Nome').AsString);
            Next;
          end;
      finally
        Free; //Destruindo o Cursor - //Aqui o SQL desaparece na tabela MON$STATEMENTS do firebird
      end;
    end;
  ShowMessage('Aqui');
end;