World Wide Study Bible
a Bible passage
13 Then one of the elders addressed me, saying, “Who are these, robed in white, and where have they come from?”
13. answered—namely, to my thoughts; spoke, asking the question which might have been expected to arise in John's mind from what has gone before. One of the twenty-four elders, representing the Old and New Testament ministry, appropriately acts as interpreter of this vision of the glorified Church.
What, &c.—Greek order, "These which are arrayed in white robes, WHO are they?"