The Royal Law is mentioned in James 2:8: It is good when we obey the royal law as found in the Scriptures: “Love your neighbor as yourself.” It is interesting that the term Royal Law could be translated as Kingly Law because it comes from the same root word as Kingdom. It could just as easily be said: “The Kingdom Rule we should obey is to: ‘Love your neighbor as yourself.”
The Pharisees asked Jesus: “Teacher, which is the most important commandment in the Law of Moses?”
Jesus replied, “‘You must love the Lord your God with all your heart, all your soul, and all your mind. This is the first and greatest commandment. A second is equally important: ‘Love your neighbor as yourself.’ The entire law and all the demands of the prophets are based on these two commandments.” (Matthew 22:36-40)
This is the Royal Law, the Kingdom Rule: Love God, love people and love yourself.
“Love your neighbor as yourself.’ No other commandment is greater than these.” Jesus