Laravel显示特定人员的消息

I've made this project using the messages panel, and I want to display the message for a specific person. My relations:

In user:
    public function Message()
    {
        return $this->belongsToMany('App\Message');
    }
In message:
    public function user()
    {
        return $this->belongsTo('App\User');
    }
And in my controller its look like:
    public function wiadomosci()
    {
        $menuClasses = ['', '', '', 'active', ''];
        $messages = Message::where('to_id','=', Auth::user()->id);
        return view('panel.wiadomosci', compact('menuClasses'))->with('messages', $messages);
    }

When I add where in $message it does not display anything to me, but when I delete it, it shows me all of the messages not assigned to that user.

@@Everything is fine now, problem solved. But I have a new problem: I would like to display the user name who send message(teacher_name) in the view, but I can only display an Id. controller:

public function wiadomosci()
{
    $menuClasses = ['', '', '', 'active', ''];
    $messages = Message::where('to_id','=', Auth::user()->id)
        ->join('teachers', 'messages.from_id', '=','teachers.id')
    ->get();
    return view('panel.wiadomosci', compact('menuClasses'))->with('messages', $messages);
}  

and in view :

@foreach($messages as $message)
            Od:{{$message->teachers_name}}
            </br>
            Tytuł:{{$message->title}}
            </br>
            opis:{{$message->contents}}
            </br>
        @endforeach

In mysql query would look like this :

SELECT teachers.name FROM messages JOIN teachers ON messages.from_id=teachers.id