To show bash version in PASE you can use this command
$
bash --version this is result
GNU bash, version 4.4.23(1)-release (powerpc-ibm-os400)
Copyright (C) 2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.