Mark 9:3-4

9:3 and his clothes became radiantly white, more so than any launderer in the world could bleach them. 9:4 Then Elijah appeared before them along with Moses, ¹  and they were talking with Jesus.

[9:4]  ¹ sn Commentators and scholars discuss why Moses and Elijah are present. The most likely explanation is that Moses represents the prophetic office (Acts 3:18-22) and Elijah pictures the presence of the last days (Mal 4:5-6), the prophet of the eschaton (the end times).