How did Peter recognize Moses and Elijah? (Mark 9:1-6)

A reader of our site asked to address a question about the event of the Transfiguration of Jesus on the mount when He spoke with Elijah and Moses:

I can’t figure out how he knew that the two men were elijah and Moses?

The passage from the Bible tells us the following:

And Jesus was saying to them, “Truly I say to you, there are some of those who are standing here who will not taste death until they see the kingdom of God after it has come with power.” Six days later, Jesus took with Him Peter and James and John, and brought them up on a high mountain by themselves. And He was transfigured before them; and His garments became radiant and exceedingly white, as no launderer on earth can whiten them. Elijah appeared to them along with Moses; and they were talking with Jesus. Peter said to Jesus, “Rabbi, it is good for us to be here; let us make three tabernacles, one for You, and one for Moses, and one for Elijah.” For he did not know what to answer; for they became terrified. (Mark 9:1-6)

Before Jesus Christ said anything, Peter admitted that those two were Moses and Elijah. He had not previously seen either one of them because they lived hundreds of years before. The disciples witnessed how Jesus talked with these two men. There remains another explanation: Jesus addressed them by name, and they also addressed Jesus and each other by names. We also address each other by name in our discussions. The fact is that Peter understood that the two men were Elijah and Moses. He asked Jesus if they should make one tabernacle for each: Jesus, Moses and Elijah. Had Peter understood something wrong, Jesus would have given explanations.

Read this article in Romanian.