The first prophecy came through Moses. I believe this is talking about Elijah. Moses was the mediator between God and the Israelites. God wrote His Law with His own finger and gave the tablets to Moses.(Exodus 32:16-19) Moses did not even make it all the way down the mountain and the people had broken Law #1 and probably, truth be told, all 613 regulations(Ex. 20-31) and Moses smashed the tablets. God was with Moses on the mountain. Do you not know that God saw the people breaking the law even as He wrote it on those tablets? After this Moses and the Levites killed three thousand of their brothers and sons. Because they did this they were ordained for service.
After the Holy Spirit came, the believers were ordained for service and (Acts 2:41) Peter baptized three thousand that day. The law brings death and Grace brings life. Moses went right back up that mountain and God gave the Law again. This time when Moses came down his face glowed so much that the people were afraid to come near him. And Jesus took them to the top of a mountain---sounds like where Moses got the Law. And Jesus appearance became so bright they were afraid. And the voice from Heaven said---in the presence of Moses and Elijah---This is my beloved Son Listen to Him. Till next time---be blessed ---c