Attach flash message to file download response in Laravel

In my code, I am returning a zip file as a streamed response:

return response()->stream(function() use ($zip){
            $zip->finish();
        });

I would like to also return a status message saying "Your zip download has started" along with the response, but I can't find a way of doing it properly in Laravel.

I am using Laravel 5.2

via Chebli Mohamed