Bhagavad Gita: Chapter 4, Verse 34

तद्विद्धि प्रणिपातेन परिप्रश्नेन सेवया |

उपदेक्ष्यन्ति ते ज्ञानं ज्ञानिनस्तत्त्वदर्शिन: ||

Glossary :

tat—the truth; 

viddhi—try to learn;

praṇipātena—by approaching a spiritual master;

paripraśhnena—by humble inquiries;

sevayā—by rendering service;

upadekṣhyanti—can impart;

te—unto you;

jñānam—knowledge;

jñāninaḥ—the enlightened;

tattva-darśhinaḥ—those who have realized the truth

Translation :

Learn the Truth by approaching a spiritual master. Inquire from him with reverence and render service unto him. Such an enlightened Saint can impart knowledge unto you because he has seen the Truth.