Sushruta Samhita
शास्त्रं गुरुमुखोद्गीर्णमादायोपास्य चासकृत् । यः कर्म कुरुते वैद्यः स वैद्योऽन्ये तु तस्कराः ॥८॥
A physician who performs actions based on the instructions received from the guru and practices repeatedly is a true physician. However, those who do not follow this principle are mere thieves in comparison.
english translation
zAstraM gurumukhodgIrNamAdAyopAsya cAsakRt । yaH karma kurute vaidyaH sa vaidyo'nye tu taskarAH ॥8॥
hk transliteration by Sanscript