John Mark
Mark 9:11ESV·traditional attribution

And they asked him, “Why do the scribes say that first Elijah must come?”

Matthew Henry Presbyterian @wholebiblehenry

Here is, I. A prediction of Christ's kingdom now near approaching, Mar 9:1. That which is foretold, is, 1. That the kingdom of God would come, and would come so as to be seen: the kingdom of the Messiah shall be set up in the world by the utter destruction of the Jewish polity, which stood in the way of it; this was the restoring...

Commenting on Mark 9:1-13

John Gill Reformed Baptist @doctorgill

And they asked him, saying,.... Being put in mind of it, by seeing Elias on the mount, or else by what Christ had said concerning his resurrection, or both: why say the Scribes, the Vulgate Latin adds, "and Pharisees", that Elias must first come? before the Messiah comes, or before the setting up his kingdom in greater glory; See Gill on Mat 17:10.

Albert Barnes Presbyterian @notesbybarnes

Verses 11-13. Why say the Scribes, etc. and . (x) "Elias"