Modified Message class extends from Phalcon\Validation\Message to enable translation.Translation service needs to be set in DI. Don't forget to add correct namespace to your $loader.

Message.php

<?php

namespace Library\Validation;


use Phalcon\DI;

/**
 * Class Message
 *
 * This is a modification of the default Validation/Message class
 * Modified to return a translated message
 *
 * User: mraspor
 * Date: 10/8/14
 * Time: 5:00 PM
 *
 * @package Library\Validation
 */
class Message extends \Phalcon\Validation\Message {

    /**
     * @return mixed
     */
    public function getMessage()
    {
        $di = DI::getDefault();

        return $di->get('translation')->_($this->_message);
    }

}