It looks like the statements are setup to do what is called Identity NAT in v6.3. I have included a link from v6.1 which is a little more descriptive. It is basically allowing you to access resources from a higher security interface on a lower security network without performing NAT. Usually statics are used for the opposite access (lower to higher).
This would be useful if you want to have the inside IP address appear as its original address when accessing DMZ resources.
One thing with your example is the netmask statements should be 255.255.255.255. It would contain a network mask if a network range was specified.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...