A pure devotee who is fully accomplished in the science of devotional service will never instruct a foolish person to engage in fruitive activities for material enjoyment, not to speak of helping him in such activities. Such a devotee is like an experienced physician, who never encourages a patient to eat food injurious to his health, even if the patient desires it.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
स्वयं निःश्रेयसं विद्वान् न वक्त्यज्ञाय कर्म हि । न राति रोगिणोऽपथ्यं वाञ्छतो हि भिषक्तमः
svayaṃ niḥśreyasaṃ vidvān na vaktyajñāya karma hi | na rāti rogiṇo'pathyaṃ vāñchato hi bhiṣaktamaḥ
SB 6.9.50