• install plugin Enhanced Text Widget;
• add code in Enhanced Text Widget textarea;
  

<?php
$my_postid = 22; //id your post
$content_post = get_post($my_postid);
$content = $content_post->post_content;
$content =apply_filters('the_content',$content);
$content = str_replace(']]>', ']]>', $content);
echo $content;
?>

Теги: php, text widget, wordprss