SB 10.45.47
sri-gurur uvaca
samyak sampadito vatsa
bhavadbhyam guru-niskrayah
ko nu yusmad-vidha-guroh
kamanam avasisyate
Translation:
The spiritual master said: My dear boys, You two have completely fulfilled the disciple’s obligation to reward his spiritual master. Indeed, with disciples like You, what further desires could a guru have?