Srimad Bhagavatam Canto 04, Chapter 29, Text 05

 SB 4.29.5

buddhim tu pramadam vidyan
 mamaham iti yat-krtam
yam adhisthaya dehe ’smin
 puman bhunkte ’ksabhir gunan
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
The great sage Narada continued: The word pramada mentioned in this regard refers to material intelligence, or ignorance. It is to be understood as such. When one takes shelter of this kind of intelligence, he identifies himself with the material body. Influenced by the material consciousness of “I” and “mine,” he begins to enjoy and suffer through his senses. Thus the living entity is entrapped.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
In material existence so-called intelligence is actually ignorance. When intelligence is cleared up, it is called buddhi-yoga. In other words, when intelligence is dovetailed with the desires of Krsna, it is called buddhi-yoga or bhakti-yoga. Therefore in Bhagavad-gita (10.10) Krsna says:
tesam satata-yuktanam
 bhajatam priti-purvakam
dadami buddhi-yogam tam
 yena mam upayanti te
“To those who are constantly devoted and worship Me with love, I give the understanding by which they can come to Me.”
Real intelligence means linking with the Supreme Personality of Godhead. When this is done, the Supreme Personality of Godhead from within gives one the real intelligence by which one can return home, back to Godhead. Intelligence in the material world is described in this verse as pramada because in material existence the living entity falsely claims things to be his. He thinks, “I am the monarch of all I survey.” This is ignorance. Actually, nothing belongs to him. Even the body and the senses do not belong to him, for they are given to him by the grace of the Lord to satisfy his different propensities through the material energy. Nothing actually belongs to the living entity, but he becomes mad after everything, claiming, “This is mine. This is mine. This is mine.” Janasya moho ’yam aham mameti. This is called illusion. Nothing belongs to the living entity, but he claims that everything belongs to him. Lord Caitanya Mahaprabhu recommends that this false intelligence be purified (ceto-darpana-marjanam). When the mirror of intelligence is polished, the real activities of the living entity begin. This means that when a person comes to the platform of Krsna consciousness, his real intelligence acts. At that time he knows that everything belongs to Krsna and nothing belongs to him. As long as one thinks that everything belongs to him, he is in material consciousness, and when he knows perfectly that everything belongs to Krsna, he is in Krsna consciousness.
Srimad Bhagavatam Canto 04, Chapter 29, Text 04
Srimad Bhagavatam Canto 04, Chapter 29, Text 06