How can I edit or extend the error message in laravel5.3?

i want to extend validation setting another field just like that:

return Validator::make($data, [

        'name' => 'required|max:255',
        'email' => 'required|email|max:255|unique:users',
        'password' => 'required|min:6|confirmed',
        'another_field' => 'validation'
    ]); 

via Chebli Mohamed