Be careful with this code since any HTTP path would be redirected to /xyz/ , also the opening " { " bracket at line 3 needs to be moved in line 2 for proper syntax.
If you need to match only "/" path use the following code instead.
This will append /xyz/ without issuing a redirect -- based on your previous comment, I'm assuming the /xyz/ path is hosted within the same pool you use for load balancing ; a redirect will be required if this is not the case
when HTTP_REQUEST {
if {[HTTP::host] eq "abc.com" && [HTTP::path] eq "/"}{ HTTP::uri "/xyz/" }
}