Srimad Bhagavatam Canto 01, Chapter 09, Text 36

SB 1.9.36

vyavahita-prtana-mukham niriksya
sva-jana-vadhad vimukhasya dosa-buddhya
kumatim aharad atma-vidyaya yas
carana-ratih paramasya tasya me ’stu
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
When Arjuna was seemingly polluted by ignorance upon observing the soldiers and commanders before him on the battlefield, the Lord eradicated his ignorance by delivering transcendental knowledge. May His lotus feet always remain the object of my attraction.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
The kings and the commanders were to stand in the front of the fighting soldiers. That was the system of actual fighting. The kings and commanders were not so-called presidents or ministers of defense as they are today. They would not stay home while the poor soldiers or mercenaries were fighting face to face. This may be the regulation of modern democracy, but when actual monarchy was prevailing, the monarchs were not cowards elected without consideration of qualification. As it was evident from the Battlefield of Kuruksetra, all the executive heads of both parties, like Drona, Bhisma, Arjuna and Duryodhana, were not sleeping; all of them were actual participants in the fighting, which was selected to be executed at a place away from the civil residential quarters. This means that the innocent citizens were immune from all effects of fighting between the rival royal parties. The citizens had no business in seeing what was going to happen during such fighting. They were to pay one fourth of their income to the ruler, whether he be Arjuna or Duryodhana. All the commanders of the parties on the Battlefield of Kuruksetra were standing face to face, and Arjuna saw them with great compassion and lamented that he was to kill his kinsmen on the battlefield for the sake of the empire. He was not at all afraid of the giant military phalanx presented by Duryodhana, but as a merciful devotee of the Lord, renunciation of worldly things was natural for him, and thus he decided not to fight for worldly possessions. But this was due to a poor fund of knowledge, and therefore it is said here that his intelligence became polluted. His intelligence could not be polluted at any time because he was a devotee and constant companion of the Lord, as is clear in the Fourth Chapter of the Bhagavad-gita. Apparently Arjuna’s intelligence became polluted because otherwise there would not have been a chance to deliver the teachings of Bhagavad-gita for the good of all polluted conditioned souls engaged in material bondage by the conception of the false material body. The Bhagavad-gita was delivered to the conditioned souls of the world to deliver them from the wrong conception of identifying the body with the soul and to reestablish the soul’s eternal relation with the Supreme Lord. Atma-vidya, or transcendental knowledge of Himself, was primarily spoken by the Lord for the benefit of all concerned in all parts of the universe.
 
Srimad Bhagavatam Canto 01, Chapter 09, Text 35
Srimad Bhagavatam Canto 01, Chapter 09, Text 37