John Gill Commentary Mark 9:14

"And when they came to the disciples, they saw a great multitude about them, and scribes questioning with them." — Mark 9:14 (ASV)

And when he came to his disciples
The other nine, who were left at the bottom of the mountain, and were waiting for him:

he saw a great multitude about them :
there was a multitude that followed him from Bethsaida here; and which, very likely, was greatly increased upon Christ's arrival in those parts, and the people hearing of it;

and the Scribes questioning with them ;
disputing and contending with them about their master, his doctrines and miracles, and their mission and authority from him; insulting them, on account of their inability to dispossess a dumb spirit, hereafter related.