Why then say the scribes that Elias must first come
Compare (Matthew 11:14); (Mark 9:11-13); (Luke 1:17); (Malachi 3:1); (Malachi 4:5-6).
All the passages must be construed together.
(1) Christ confirms the specific and still unfulfilled prophecy of (Malachi 4:5-6): "Elias shall truly first come and restore all things." Here, as in Malachi, the prediction fulfilled in John the Baptist, and that yet to be fulfilled in Elijah, are kept distinct.
(2) But John the Baptist had come already, and with a ministry so completely in the spirit and power of Elijah's future ministry (Luke 1:17) that in an adumbrative and typical sense it could be said: "Elias is come already."
Compare (Matthew 10:40); (Philemon 1:12); (Philemon 1:17) where the same thought of identification, while yet preserving personal distinction, occurs. (John 1:27).