BG Chap 13 - The one qualified to understand these topics
Only the devotee of Kṛṣṇa can understand these topics of description of the field, the process for gaining knowledge, and the object of knowledge – the two knowers of the field. Knowing these three topics, understanding them by discrimination, the devotee become qualified for the Lord’s nature (mad-bhāvāya) – for being free from material existence. The jñānī can also understand these topics if he is endowed with devotion and would merge with the Lord (mad bhāvāya). But the pure devotee who knows these topics becomes qualified for prema which is another meaning of mad-bhāvāya.