Bg 10.14

sarvam etad rtam manye
yan mam vadasi kesava
na hi te bhagavan vyaktim
vidur deva na danavah

Word for word: 
sarvam — all; etat — this; rtam — truth; manye — I accept; yat — which; mam — unto me; vadasi — You tell; kesava — O Krishna; na — never; hi — certainly; te — Your; bhagavan — O Personality of Godhead; vyaktim — revelation; viduh — can know; devah — the demigods; na — nor; danavah — the demons.

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
O Krishna, I totally accept as truth all that You have told me. Neither the demigods nor the demons, O Lord, can understand Your personality.

Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Arjuna herein confirms that persons of faithless and demonic nature cannot understand Krishna. He is not known even by the demigods, so what to speak of the so-called scholars of this modern world? By the grace of the Supreme Lord, Arjuna has understood that the Supreme Truth is Krishna and that He is the perfect one. One should therefore follow the path of Arjuna. He received the authority of Bhagavad-gita. As described in the Fourth Chapter, the parampara system of disciplic succession for the understanding of Bhagavad-gita was lost, and therefore Krishna reestablished that disciplic succession with Arjuna because He considered Arjuna His intimate friend and a great devotee. Therefore, as stated in our Introduction to Gitopanisad, Bhagavad-gita should be understood in the parampara system. When the parampara system was lost, Arjuna was selected to rejuvenate it. The acceptance by Arjuna of all that Krishna says should be emulated; then we can understand the essence of Bhagavad-gita, and then only can we understand that Krishna is the Supreme Personality of Godhead.