Static ARP (Address Resolution Protocol) entries reduce ARP processing and preclude man-in-the-middle attacks for the specified addresses.
Navigate to the ARP entry configuration:
From the CLI
# set network interface ethernet ethernet1/5 layer3 arp 10.101.10.10 hw-address F0:1F:AF:02:96:36
Note: It's not possible to change the Palo Alto Networks interface MAC address.