@nollipfsense maybe? Maybe he just needs to set a reservation in his dhcp ;)
Its not unheard of practice from a security point of view on firewalled segments that will have different rules to be different. So your not actually creating pinholes for specific IPs on a vlan. Either the whole vlan has access, or nothing does. And if something needs access to some other vlan or specific ips and services on a different - put devices that need this access in a different vlan where you can create rules for the whole vlan vs specific IPs on the vlan.
But it does seems like a leap in concerns for smaller network, maybe in a datacenter or larger enterprise with very strict security policies.
dhcp reservation would ensure his specific device(s) would be the only thing with that IP(s) that are allowed to talk to the server on port X. If really concerned, setting up static arp, and sure also run arpwatch to be alerted if the mac for IP xyz changes.
edit: If you were really concerned - and your devices are wired, you could setup port security on the switch ports. This would prevent a device from changing its mac and gaining access to the network via different mac/ip combo that matched your firewall rules.