Did Jesus or 'an expert in the law' first share the greatest commandments? In Luke 10.25-29 you have a teacher of the law asking Jesus how to inherit eternal life and then that same teacher of the law answering the question with the two greatest commandments 

But then in Matthew 22.34-40 you have a pharisee (and an expert in the law) asking Jesus what the greatest commandment is and Jesus then answering with the greatest commandments.

So 1) are these two different situations or the same situation described differently? and 2) who first shared the greatest commandments, Jesus, the expert in the law or someone else?
What we today call the "two great commandments" were well-known in Jesus' day

Both commandments had been previously given by Jehovah.


  1st Great Commandment:&emsp;And thou shalt love the Lord thy God with all thine heart, and with all thy soul, and with all thy might. (KJV Deut. 6:5)
  
  2nd Great Commandment:&emsp;Thou shalt not avenge, nor bear any grudge against the children of thy people, but thou shalt love thy neighbour as thyself: I am the Lord. (KJV Lev. 19:18)


So it depends on what you mean by "shared."


Jehovah was the first to express the ideas.
Moses was the first to write the ideas down.
Whomever taught the lawyers of the New Testament the doctrine were before Jesus or the lawyers.


As I led off, the two great commandments were well-known doctrines of the day.  They were not introduced first by either Jesus or the lawyers in the New Testament, but were introduced by Moses via Jehovah in the Old Testament and would have been regularly studied in the rabbinical schools.  I believe it is reasonable to assume that both the lawyers and Jesus learned the two commandments as children.

&hellip; Which is why Jesus' response to the lawyer in Luke 10:26 makes perfect sense.

However, if what you're asking is, "but in that specific situation (or situations), who introduced the idea first, the lawyers or Jesus?" that I can't help you with.  I hope I was a spiritual observer, but that veil has been drawn and I doubt there's enough historical evidence to be definitive.