I've actually been waiting for something about the "Golden Rule" to be published on this forum. To me it's basically due Unto others as you would have them do Unto you.
Yes, the original rule is found in Exodus 21:24-25. It's also called the Law of Retribution.
Jesus only put it in "other words."
Do to other's as you would want them to do to you is the same as eye for eye just in more colorful language.
12 So then, whatever you desire that others would do to and for you, even so do also to and for them, for this is (sums up) the Law and the Prophets. Matthew 7:12
The golden rule indicates that the horizon of Christian action is universal. Human beings are partners. Thus by no means do we have in the Sermon on the Mount an ethic that is to be practiced only in the protected inner sanctuary of the Christian community.
The "horizon" is only within Covenant brethren. The Word of God was not written to and for anyone but the Bride of Christ who is Israel.
Gentile believers are grafted in and when the Times of the Gentiles are ended God turns His full attention back to Israel, sends at least two prophets/witnesses whom God uses to finally show Israel that this Jesus was truly their Messiah (but there were already Israelites in the first century who accepted Christ and Messiah as their Lord and Savior.
Gentile believers were grafted into the Olive Tree which represents the Nation of Israel.
I like to think it's part of our everyday life.
It's almost impossible for brethren to fellowship when they don't see the same Jesus and say the same thing as God. That's why the Holy Spirit said this:
42 And they continued stedfastly in the apostles’ doctrine and fellowship, and in breaking of bread, and in prayers. Acts 2:42.
The 'apostles' doctrine was unified. They all saw the same Jesus and said the same thing as God and the result was there was fellowship, excellent communion and unity of mealtime (whichever way you want to take it), and their prayers were unhindered.
Not so today.
But the Lord knows them that are His.