run-help is a function that invoke the manpage concerning the first command in current command line, and when man page is quit, that command line keeps as it were before run-help

to load run-help
<code>
autoload -U run-help
</code>

now on a command line if you type ESC-h, ESC-H, ALT-h or ALT-H
it will show you the manpage that then get you back to your line.