How to translate “Permanent link to” text

one possible way:

<?php
$link_text = sprintf( 
                 __( 'Permanent link to %s', 'youthemetextdomain'),
                 get_the_title() ); ?>

<h3><a
    href="https://wordpress.stackexchange.com/questions/128312/<?php the_permalink(); ?>"
    title="<?php the_title_attribute(); ?>"
><?php echo $link_text; ?></a></h3>

get_the_title() returns the title instead of displaying it. The double-underscore function is how WordPress allows strings to be extracted from a theme or plugin for translation.