A.T. Robertson Commentary Mark 9:4

"And there appeared unto them Elijah with Moses: and they were talking with Jesus." — Mark 9:4 (ASV)

Elijah with Moses (Ελειας συν Μωυσε). Matthew and Luke have "Moses and Elijah." Both, as a matter of fact were prophets and both dealt with law. Both had mysterious deaths. The other order in Mr 9:5.