What did Elija and Moses say to Jesus at the time of the transfiguration?

I wondered this today when I heard the mass reading regarding the transfiguration. I was deliberately trying to put more thought into the readings for today and this issue stood out for some reason. Matthew depicted the prophets in conversation with Jesus who was transfigured. I honestly cannot give an intelligent answer but did find some interesting facts in my reading and research on the net. First, that Moses represented the Hebrew law at this supernatural event. The 10 commandments, and all Hebrew laws that were later derived from this and Jewish traditions, are represented by the vision of Moses.

One source seemed to indicate that Elijah represented prophets who had come before Christ himself. This might imply that Elijah's presence served the purpose of somehow balancing and complementing Moses'. I would feel very pleased if I had the theological background to expound on this further.

I did come upon, however, a very good reference that was copywrite 1999, by Robert I. Bradshaw in England. It is an excellent essay on Elijah. In this essay was a type of bible concordance regarding New Testament references to Elijah. This lead me to look up the corresponding reference in Luke chapter 9 verse 30 (Luke was read in Mass in 2010, as I recall; today's Mass reading included the verse from Matthew chapter 17) which depicts the Transfiguration. This actually answered my question, and states that the prophets and Jesus were talking about his departure, i.e. his passion and death. Of all the things that I had thought they might have discussed, I did not consider this. They were discussing a future event. That would fit well, with the fact that Moses and Elijah were prophets.

On a final note for this essay, it is a misconception apparently that I had that a prophet is defined as one who has visions of future events. I stand corrected, (via Answers.com) and a prophet is actually one who speaks for God or through whom God speaks. Although Luke did state generally what Moses, Elijah and Jesus were saying, no one knows exactly what they said or needed to discuss. These are all things outside our usual experience, and my point in bringing this up is to stimulate thought along spiritual lines. I have not tried to judge the account of the transfiguration as to whether we are commanded to take it literally or not. Interestingly, our Pastor's homily today did seem to touch on this point (in a somewhat oblique manner). Such is the nature of our journeys in spirituality and faith.