“Jesus asked them.
‘What are you
καὶ ἐπηρώτησεν αὐτούς Τί συνζητεῖτε πρὸς αὑτούς;
This is also unique to Mark, who said that Jesus asked or questioned his disciples (καὶ ἐπηρώτησεν αὐτούς) about what they were arguing, disputing, or discussing with the Scribes (Τί συνζητεῖτε πρὸς αὑτούς). However, there was no indication of what they were discussing here. Perhaps it was about the story to come of why the disciples were not able to cast out the evil spirit.