after die and dump getting null value ?

Output

^ null

Basically I want fetch record using routekeyname in url...In url key name is shown but data is not diplaying... This is my show function

    public function show($post)
    {
        // $articles = CMSPost::findOrFail($id);
        $articles = CMSPost::find($post);

        dd($articles);
        // return view('cms.post.show',array('articles' => $articles));
    }

And this is my Model

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\SoftDeletes;

class CMSPost extends Model
{
	use SoftDeletes;


	protected $dates = ['deleted_at'];
	protected $table ='cms_posts';
    protected $primaryKey = 'id';

	protected $fillable = array('category_id','title','author','show_date','image','description','status','user_id','slug',
        'visit_count','aslug','subcategory_id','draft');   
    
    
    /**
     * Get the route key for the model.
     *
     * @return string
     */
    public function getRouteKeyName()
    {
        return 'aslug';
    }

    public function category()
     {
         return $this->belongsTo('App\CMSCategory','category_id');
     }  


     public function user(){

         return $this->belongsTo('App\User','user_id');
     }

     public function mediaLibrary(){

         return $this->belongsTo('App\mediaLibrary','image');

     }
     
     // public function tags()
     //     {
     //         return $this->belongsToMany(CMSTag::class); 
     //     }  


}

And this is my route

Route::group(['prefix' => 'cms',  'middleware' => 'auth'], function()
{
    Route::resource('/post','CMSPostController');
}