VOLT, Phalcon, XSS how to fix?

Question

PHP

An example for everyone.
In general, I do not know what crutch to come up with here. Problem:
I'm outputting a post. But before the output, I run the post through the XSS filter built into VOLT:
{{ post.message|e }}
But the point is that post.message has MarkDown markup. Which needs to be converted to valid HTML.
The first option is what I do:
{{ mark.Down(post.message) }}
But this way you can shove XSS.
I decided to run through the XSS filter before passing post.message to the markDown::parse() function:

{% set post.message = post.message|e %}

<div class="post-text">
    {{ markDown.parse(post.message) }}
</div>

But for some reason MarkDown markup gets corrupted. (The output is a line processed by MarkDown, but HTML markup tags are also escaped by the filter)
Why is that? Logically, this shouldn't be the case.
The compiled template looks like this:

<?php $post->message = $this->escaper->escapeHtml($post->message); ?>

<div class="post-text">
    <?php echo $this->markDown->parse($post->message); ?></p>
</div>

My head is already spinning. what's wrong here?

Answer 1

How is markDown initiated? What is it?
And so it works?

{% set post_message = post.message|e %} {# не портить внутренности объекта post #}

<div class="post-text">
    {{ markDown.parse(post_message ) }}
</div>