If you want to understand, then Kṛṣṇa says here:
- tad viddhi praṇipātena
- paripraśnena sevayā
- upadekṣyanti te jñānaṁ
- jñāninas tattva-darśinaḥ
- (BG 4.34)
The same tattva. You have to approach a person who has seen tattva, tattva-darśinaḥ. So that tattva-darśī already explained. Bhaktyā mām abhijānāti (BG 18.55). One can become tattva-darśī simply by devotional service.
So for coming to the platform of devotional service one has to make some sacrifice. That is called tapasya. Tapasya means voluntarily accepting some difficult things. That is called tapasya. Therefore those who have not taken to that, those who have taken Bhagavad-gītā as a table talk, they cannot understand. Not Bhagavad-gītā should be preached amongst them.
Therefore Kṛṣṇa is warning, idaṁ te na atapaskāya nābhaktāya. Idaṁ te nātapaskāya nābhaktāya kadācana: "Never describe. Never described this Bhagavad-gītā." Kṛṣṇa said in the previous verse . . . people will not be able to understand. Kṛṣṇa says, sarva-dharmān parityajya mām ekaṁ śaraṇaṁ vraja (BG 18.66). This simple fact cannot be understood by any man who has not undergone some austerities, penances, and who has not become a devotee. It is not possible. Therefore Kṛṣṇa is warning, "Don't speak to these nonsense. They will not understand."
But a devotee of Kṛṣṇa tries to make them devotee. Because Kṛṣṇa, in the next verse, says, ya idaṁ paramaṁ guhyaṁ mad-bhakteṣv abhidhāsyati (BG 18.68). Mad-bhakteṣv abhidhāsyati. Here in this verse it is said, nābhaktāya: "Don't speak this truth of Bhagavad-gītā to the abhaktas," but if you can speak to the bhaktas . . . ya idaṁ paramaṁ guhyam.
Paramaṁ guhyam. It is the most confidential knowledge, most confidential part of Vedic knowledge. It is said in the beginning, sarva-guhyatamam. Sarva-guhyatamam: "Most confidential." So paramaṁ guhyaṁ mad-bhakteṣu. Because from the beginning it is simply said, "Only the bhaktas can understand." Therefore it should be preached among the bhaktas. Mad-bhakteṣu abhidhāsyati, bhaktiṁ mayi parāṁ kṛtvā mām eva eṣyasi, eṣyati asaṁśayaḥ.
So this is another opportunity. Just create, everyone, everyone, especially . . . Caitanya Mahāprabhu said, bhārata-bhūmite manuṣya-janma haila yāra (CC Adi 9.41): "Anyone who has taken birth in this holy land of Bhāratavarṣa . . ." janma sārthaka kari' kara para-upakāra. This is the injunction of Caitanya Mahāprabhu that, "First of all, make your life perfect. Just try to understand what is Kṛṣṇa and what is Bhagavad-gītā, and make your life practical in understanding Bhagavān and the bhakti." Janma sārthaka kari': "Then go and preach all over the world." Paropakāra.