posts in the single.php

Hello I’m new and I’ve problem with show posts on the curent post for exaplme I have code in single.php:
(this is the post number f.e ‘p=5’)
….
<?php if (have_posts()) : while (have_posts()) : the_post(); ?>

/*now i’d like show on this post another post and i do .*/

<?php if ($post->ID==5) : if(query_posts(‘p=7’)): the_post(); the_content(); endif; endif;?>
….

<?php endwhile; ?><?php endif; ?>
…
/*and display me the post number 7 on post 5 – that’s ok*/
/*but i want display another post also on post 31 and the same code above don’t display me another post contents – > why? */
/*i’ve treid use “multiple loops” but don’t work */
/* how add another post contents in this post ? */