$user = Users::findFirst($this->session->get("auth-id"));
Tag::displayTo("about", $user->about);
use Phalcon\Forms\Form;
use Phalcon\Forms\Element\Text;
// форма
$user = Users::findFirst($this->session->get("auth-id"));
$form = new Form($user);
$form->add(new Text('about'));
// вывод
<?php echo $form->render('about'); ?>
// сохранение, например
$form->bind($_POST, $user);
if ($form->isValid())
{
$user->save();
}