SB 11.18.38

duḥkhodarkeṣu kāmeṣu
 jāta-nirveda ātmavān
ajijñāsita-mad-dharmo
 muniṁ gurum upavrajet
Synonyms: 
duḥkha — unhappiness; udarkeṣu — in that which brings as its future result; kāmeṣu — in sense gratification; jāta — arisen; nirvedaḥ — detachment; ātma-vān — desiring spiritual perfection in life; ajijñāsita — one who has not seriously considered; mat — Me; dharmaḥ — the process of obtaining; munim — a wise person; gurum — a spiritual master; upavrajet — he should approach.
Translation: 
One who is detached from sense gratification, knowing its result to be miserable, and who desires spiritual perfection, but who has not seriously analyzed the process for obtaining Me, should approach a bona fide and learned spiritual master.
Purport: 

In the previous verses Lord Kṛṣṇa described the duty of one who has developed perfect knowledge. Now Lord Kṛṣṇa discusses the situation of one who, desiring self-realization, has become detached from material life but lacks perfect knowledge of Kṛṣṇa consciousness. Such a detached person desiring self-realization must approach the lotus feet of a bona fide spiritual master in Kṛṣṇa consciousness, and then he will quickly come to the standard of perfect understanding. One who is seriously inclined toward spiritual perfection should not hesitate to adopt the regular discipline necessary for achieving the highest perfection in life.