Language file in rule group error?

Is there a way to be able to use a lang() in a rule group to display errors?

In my Config/Validation.php

PHP Code:

public $clientRegistration = [
        'first_name' => ['label' => 'First Name', 'rules' => 'trim|required|min_length[2]|clients_name_check'],
        'last_name' => ['label' => 'Last Name', 'rules' => 'trim|required|min_length[2]|clients_name_check'],
        'birth_date' => ['label' => 'Birth Date', 'rules' => 'trim|required|check_date_format', 'errors' => ['check_date_format' => lang('Misc.field_not_formatted_correctly')]],
    ]; 


I am getting an error in my IDE:

"expression is not allowed as field default value"

Maybe I am missing on how to do this.

Thank you in advanced.