Laravel how can I make my video_id column equal to id of my videos table?

I'm new to laravel, right now I'm stuck on getting video_id on my posts table where I should make it equal to id on my videos table. posts table = http://ift.tt/2am42fD videos table = http://ift.tt/2ayoUUr Route: displaying video ID when i post it:

Route::get('/test/{videoID}', function($videoID) {
$video = Video::where('id', $videoID)->firstOrFail();
$posts = Post::all();
return View::make('layouts.viewvideo')->with(['video' => $video, 'posts' => $posts]);});

PostController:

public function postCreatePost(Request $request) {

    $post = new Post();
    $post->body = $request['body'];
    $request->user()->posts()->save($post);
    return redirect()->back();

Post view:

@foreach($video->posts as $post)
        <article class="post" data-postid="">
            <div class="postbody">
                <p></p>
            </div>
            <?php
            $test = preg_replace('/([^\s]{20})(?=[^\s])/', '$1'.'<wbr>', $post->body);
            ?>
            <div class="info">
                Posted by  on 
            </div>
        </article>
    @endforeach

I tried to edit video_id column on my posts table and change it equal to id of my video and it worked, but how can I automatically assign it once I create post on a specific video? Thank you.

via Chebli Mohamed