Trying to get property of non-object laravel on command dispatch

I am using "Mapping Command Properties From Requests" getting this error

Trying to get property of non-object

My Code

use App\Command\CreateSomethingCommand;

public function store(Request $request)
{
$this->dispatchFrom(CreateSomethingCommand::class,$request,['user'=>Auth::User()->id]);
.....
}

Where as the command stated at laravel http://ift.tt/1TlFt6s

Please Help!

via Chebli Mohamed