Get ID from hasMany relation

good morning. I have two tables relations,

Articles hasMany Comments

MySQL Articles table
+---------+------------------+--------------------------+
|    ID   |  Judul           |        Isi               |
+---------+------------------+--------------------------+
|    1    |  Penyakit Kucing |  Penyakit ini disebabkan |
|         |                  |     bla...bla...         |
|---------|------------------|--------------------------|

MySQL Comments table
+---------+--------------+------------------+-----------------------+
|    ID   |  article_id  |  Judul           |   Komentar            |
+---------+--------------+------------------+-----------------------+
|    1    |  1           |  Penyakit kucing |   apa penyebabnya     |
|    2    |  1           |  Penyakit kucing |  bagaimana solusinya  |
|---------|--------------|------------------|-----------------------+

inside TableMethod

Articles Table
<?php
class ArticlesTable extends Table
{
   public function initialize(array $config)
   {
      $this->hasMany('Comments', [
            'foreignKey' => 'article_id'
        ]);
    }
}
?>

Comments Table
<?php
class CommentsTable extends Table
{
   public function initialize(array $config)
   {
      $this->belongsTo('Articles', [
            'foreignKey' => 'article_id'
      ]);
   }
}
?>

I want to add comments called from

View.ctp in Articles, then get ID articles to save in CommentsTable

here’s CommentsController

<?php
class CommentsController extends AppController
{
    public function add($id = null)   //reference ID from View.ctp (ArticlesController)
    {
        $comment = $this->Comments->newEntity();
	$judulByID = $this->Articles->get($id, ['contain' => []]);   //shown error SQL builder to get ID  from View.ctp (ArticlesController)
	$isiByID = $this->Articles->get($id, ['contain' => []]);
	$comment->article_ID = $this->Articles->get($id, ['contain' => []]);
	$comment->Judul = $this->Articles->find()->select(['Judul' => $judulByID]);
	$comment->Isi = $this->Articles->find()->select(['Isi' => $isiByID]);
	$comment->Dibuat = (Time::now())->i18nFormat('dd-MM-yyyy HH:mm:ss');
        if ($this->request->is('post')) {
            $comment = $this->Comments->patchEntity($comment, $this->request->getData());
            if ($this->Comments->save($comment)) {
                $this->Flash->success(__('Komentar berhasil disimpan.'));

                return $this->redirect(['action' => 'index']);
            }
            $this->Flash->error(__('Komentar gagal disimpan.'));
        }
        $articles = $this->Comments->Articles->find('list', ['limit' => 20]);
        $users = $this->Comments->Users->find('list', ['limit' => 20]);
        $this->set(compact('comment', 'articles', 'users'));
    }
}
?>

The error messages shown below

Notice (1024): Undefined property: CommentsController::$Articles in C:\xampp\htdocs\klinikucing\src\Controller\CommentsController.php on line 32 [CORE\src\Controller\Controller.php, line 388]

Call to a member function get() on boolean Error

Documentation API
Error in: ROOT\src\Controller\CommentsController.php, line 32 

I hopefull someone give fix the error, thanx for your help…

Use $this->Comments->Articles, just like near the end of the function.