how server can receive hits from the source ip address?

The F5 needs to be setup to be the gateway of the server network.

So all traffic destined to hit the server needs to go through the F5 and there is no routes do the server via any other method. On the F5 you then setup forwarding VIPs. If you require SNAT to be turned on for load balancing to work, then you won't be able to make this work.

If it's a HTTP VIP, you can configure X-Forwarded-For on the HTTP profile and tell the webserver to listen for that information.