Rashi on II Kings
The disciples of the prophets said. The miracles that were performed through him, he continues to list. Our Rabbis said, that from here [we deduce] that Geichazi would reject the students [who came] before him,1I.e., many of the students who came previously, found Geichazi’s behavior and bad character repulsive and did not stay while he was around. and when he was banished, many students came, and the place became cramped on account of them.2See Maseches Sotah 47a.