Shiva Purana
गुर्वनुज्ञाविरहितं चोरवत्सकलं भवेत् । गुरोरपि विशेषज्ञं यत्नाद्गृह्णीत वै गुरुम् ९७ ।
Without the permission of the preceptor, anything taken is a theft. One shall accept as one’s preceptor a person who knows many special things.
english translation
gurvanujJAvirahitaM coravatsakalaM bhavet । gurorapi vizeSajJaM yatnAdgRhNIta vai gurum 97 ।
hk transliteration by Sanscript