nanu — certainly; artha — of their true welfare; kovidāḥ — expert knowers; brahman — O brāhmaṇa; varṇāśrama-vatām — among those engaged in the varṇāśrama system; iha — in this world; ye — who; mayā — by Me; guruṇā — as the spiritual master; vācā — through his words; taranti — cross beyond; añjaḥ — easily; bhava — of material life; arṇavam — the ocean.

Translation

“Certainly, O brāhmaṇa, of all the followers of the varṇāśrama system, those who take advantage of the words I speak in My form as the spiritual master and thus easily cross over the ocean of material existence best understand their own true welfare.”

Bhaktivedanta Purport

By Śrīla Prabhupāda

One’s father is a natural object of reverence, as is a religious leader who initiates one into sacred ceremonies and instructs one in general wisdom. But ultimately the bona fide spiritual master, learned in the transcendental science and thus able to take one across the ocean of birth and death to the spiritual world — such a guru is most deserving of worship and respect, for he is the direct representative of the Supreme Personality of Godhead, as stated here.