To serve the spiritual master the disciple should learn cleanliness, austerity, tolerance, silence, study of Vedic knowledge, simplicity, celibacy, nonviolence, and equanimity in the face of material dualities such as heat and cold, happiness and distress.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
शौचं तपस्तितिक्षां च मौनं स्वाध्यायमार्जवम् । ब्रह्मचर्यमहिंसां च समत्वं द्वन्द्वसंज्ञयोः
śaucaṃ tapastitikṣāṃ ca maunaṃ svādhyāyamārjavam | brahmacaryamahiṃsāṃ ca samatvaṃ dvandvasaṃjñayoḥ
SB 11.3.24