Specific IP Connection to SSH Using Firewalld Rich Rules
1sudo firewall-cmd --add-rich-rule 'rule family="ipv4" source address="192.168.10.9" service name="ssh" accept' --permanent
2sudo firewall-cmd --remove-service ssh --permanent ## needed, otherwise ssh will still be allowed for all
3sudo systemctl reload firewalld
See details in https://access.redhat.com/discussions/1342573