Mark 9:4

4 Moreover there appeared to them Elijah accompanied by Moses; and the two were conversing with Jesus,

Mark 9:4 Meaning and Commentary

Mark 9:4

And there appeared unto them Elias with Moses
Or Moses and Elias, as all the Oriental versions read, as in Mt. 17:3, (See Gill on Matthew 17:3):

and they were talking with Jesus;
concerning his decease, and what he was to do and suffer at Jerusalem, and of which he himself had lately talked with his disciples; so that this might have been a confirmation of these things to them; (See Gill on Matthew 17:3).

Mark 9:4 In-Context

2 Six days later, Jesus took with Him Peter, James, and John, and brought them alone, apart from the rest, up a high mountain; and in their presence His appearance underwent a change.

3 His garments also became dazzling with brilliant whiteness--such whiteness as no bleaching on earth could give.

4 Moreover there appeared to them Elijah accompanied by Moses; and the two were conversing with Jesus,

5 when Peter said to Jesus, "Rabbi, we are thankful to you that we are here. Let us put up three tents--one for you, one for Moses, and one for Elijah."

6 For he knew not what to say: they were filled with such awe.