SB 6.7.15
athaham amaracaryam
agadha-dhisanam dvijam
prasadayisye nisathah
sirsna tac-caranam sprsan
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
King Indra said: Therefore with great frankness and without duplicity I shall now bow my head at the lotus feet of Brhaspati, the spiritual master of the demigods. Because he is in the mode of goodness, he is fully aware of all knowledge and is the best of the brahmanas. Now I shall touch his lotus feet and offer my obeisances unto him to try to satisfy him.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Coming to his senses, King Indra realized that he was not a very sincere disciple of his spiritual master, Brhaspati. Therefore he decided that henceforward he would be nisatha, nonduplicitous. Nisathah sirsna-tac-caranam sprsan: he decided to touch his head to the feet of his spiritual master. From this example, we should learn this principle enunciated by Visvanatha Cakravarti Thakura:
yasya prasadad bhagavat-prasado
yasyaprasadan na gatih kuto ’pi
“By the mercy of the spiritual master one is benedicted by the mercy of Krsna. Without the grace of the spiritual master, one cannot make any advancement.” A disciple should never be a hypocrite or be unfaithful to his spiritual master. In Srimad-Bhagavatam (11.17.27), the spiritual master is also called acarya. Acaryam mam vijaniyan: the Supreme Personality of Godhead says that one should respect the spiritual master, accepting him as the Lord Himself. Navamanyeta karhicit: one should not disrespect the acarya at any time. Na martya-buddhyasuyeta: one should never think the acarya an ordinary person. Familiarity sometimes breeds contempt, but one should be very careful in one’s dealings with the acarya. Agadha-dhisanam dvijam: the acarya is a perfect brahmana and has unlimited intelligence in guiding the activities of his disciple. Therefore Krsna advises in Bhagavad-gita (4.34):
tad viddhi pranipatena
pariprasnena sevaya
upadeksyanti te jñanam
jñaninas tattva-darsinah
“Just try to learn the truth by approaching a spiritual master. Inquire from him submissively and render service unto him. The self-realized soul can impart knowledge unto you because he has seen the truth.” One should fully surrender unto the spiritual master. and with service (sevaya) one should approach him for further spiritual enlightenment.