laravel custom validation

'email' => 'required|email|unique:users,email',
//@sujay

 @if ($errors->any())
     @foreach ($errors->all() as $error)
         <div>{{$error}}</div>
     @endforeach
 @endif

public function store()
{
    $this->validate(request(), [
        'song' => [function ($attribute, $value, $fail) {
            if ($value <= 10) {
                $fail(':attribute needs more cowbell!');
            }
        }]
    ]);
}

namespace App\Rules;

use Illuminate\Contracts\Validation\Rule;

class GreaterThanTen implements Rule
{
    // Should return true or false depending on whether the attribute value is valid or not.
    public function passes($attribute, $value)
    {
        return $value > 10;
    }

    // This method should return the validation error message that should be used when validation fails
    public function message()
    {
        return 'The :attribute must be greater than 10.';
    }
}