So when there is description of the Lord that He is formless, He is formless means He is not of this form. He has got a sac-cid-ānanda-vigrahaḥ (Bs 5.1), a different element. Therefore He's called pavitra. And paramaṁ bhavān: "You are the Supreme Original." Puruṣaṁ śāśvataṁ divyam ādi-devam ajaṁ vibhum. So "You are Puruṣa." Puruṣa means enjoyer. "In the Vedic literature, about Yourself . . ." āhus tvām ṛṣayaḥ sarve, "all the great sages accept You, the Supreme Lord." Āhus tvām ṛṣayaḥ sarve devarṣir nāradaḥ (BG 10.13).
Devarṣir nārada. I have already spoken to you about Nārada. He has also accepted Him. That means authorities. He's quoting authorities. Not that, "I am personally accepting you as such, but there are many authorities. Many authorities."
So we have to understand about the science of God from the extraordinary activities and confirmed by the authorities, accepted by the revealed scriptures. Then we have to accept. You see? Not blindly. So Arjuna is giving such evidences. You see? Asito devalo vyāsaḥ svayaṁ caiva bravīṣi me: "You are accepted by such authorities like that, and I have the opportunity that I hear all this from You directly. I am fortunate enough that I am become Your . . . I am related in friendship with You, and I am hearing."
So here is the evidence. Now, if you want to study Bhagavad-gītā, then you have to accept all these, this statement of Arjuna. Because Bhagavad-gītā was explained directly to Arjuna, and if you don't accept the appreciation of the direct person who heard Bhagavad-gītā, then whom do we believe? Suppose I have heard something directly from one person. So what I am saying, another person who has no direct relation, he's also saying. Whom do you believe? You have to believe the person who has directly heard. So here there is no doubt about it, that Arjuna directly heard Kṛṣṇa, and his appreciations are recorded here.