Srimad Bhagavatam Canto 10, Chapter 80, Text 41

SB 10.80.41

etad eva hi sac-chisyaih
 kartavyam guru-niskrtam
yad vai visuddha-bhavena
 sarvarthatmarpanam gurau
 
Translation: 
 
This indeed is the duty of all true disciples: to repay the debt to their spiritual master by offering him, with pure hearts, their wealth and even their very lives.
 
Purport: 
 
One engages one’s body to realize one’s purposes. The body is also the basis of the material conception of “I,” while one’s fortune is the basis of the conception of “mine.” Thus by offering everything to the spiritual master, one realizes one’s self to be an eternal servant of the Lord. The spiritual master does not exploit the disciple but rather engages him fully in Krsna consciousness for the disciple’s eternal benefit.
Srimad Bhagavatam Canto 10, Chapter 80, Text 40
Srimad Bhagavatam Canto 10, Chapter 80, Text 42