SB 2.5.10

nānṛtaṁ tava tac cāpi
 yathā māṁ prabravīṣi bhoḥ
avijñāya paraṁ matta
 etāvat tvaṁ yato hi me
Word for word: 
na — not; anṛtam — false; tava — of yours; tat — that; ca — also; api — as you have stated; yathā — in the matter of; mām — of myself; prabravīṣi — as you describe; bhoḥ — O my son; avijñāya — without knowing; param — the Supreme; mattaḥ — beyond myself; etāvat — all that you have spoken; tvam — yourself; yataḥ — for the reason of; hi — certainly; me — about me.
Translation: 
Whatever you have spoken about me is not false because unless and until one is aware of the Personality of Godhead, who is the ultimate truth beyond me, one is sure to be illusioned by observing my powerful activities.
Purport: 

“The frog in the well” logic illustrates that a frog residing in the atmosphere and boundary of a well cannot imagine the length and breadth of the gigantic ocean. Such a frog, when informed of the gigantic length and breadth of the ocean, first of all does not believe that there is such an ocean, and if someone assures him that factually there is such a thing, the frog then begins to measure it by imagination by means of pumping its belly as far as possible, with the result that the tiny abdomen of the frog bursts and the poor frog dies without any experience of the actual ocean. Similarly, the material scientists also want to challenge the inconceivable potency of the Lord by measuring Him with their froglike brains and their scientific achievements, but at the end they simply die unsuccessfully, like the frog.

Sometimes a materially powerful man is accepted as God or the incarnation of God without any knowledge of the factual God. Such a material assessment may be gradually extended, and the attempt may reach to the highest limit of Brahmājī, who is the topmost living being within the universe and has a duration of life unimaginable to the material scientist. As we get information from the most authentic book of knowledge, the Bhagavad-gītā (8.17), Brahmājī’s one day and night is calculated to be some hundreds of thousands of years on our planet. This long duration of life may not be believed by “the frog in the well,” but persons who have a realization of the truths mentioned in the Bhagavad-gītā accept the existence of a great personality who creates the variegatedness of the complete universe. It is understood from the revealed scriptures that the Brahmājī of this universe is younger than all the other Brahmās in charge of the many, many universes beyond this, but none of them can be equal to the Personality of Godhead.

Nāradajī is one of the liberated souls, and after his liberation he was known as Nārada; otherwise, before his liberation, he was simply a son of a maidservant. The questions may be asked why Nāradajī was not aware of the Supreme Lord and why he misconceived Brahmājī to be the Supreme Lord, although factually he was not. A liberated soul is never bewildered by such a mistaken idea, so why did Nāradajī ask all those questions just like an ordinary man with a poor fund of knowledge? There was such bewilderment in Arjuna also, although he is eternally the associate of the Lord. Such bewilderment in Arjuna or in Nārada takes place by the will of the Lord so that other, nonliberated persons may realize the real truth and knowledge of the Lord. The doubt arising in the mind of Nārada about Brahmājī’s becoming all-powerful is a lesson for the frogs in the well, that they may not be bewildered in misconceiving the identity of the Personality of Godhead (even by comparison to a personality like Brahmā, so what to speak of ordinary men who falsely pose themselves as God or an incarnation of God). The Supreme Lord is always the Supreme, and as we have tried to establish many times in these purports, no living being, even up to the standard of Brahmā, can claim to be one with the Lord. One should not be misled when people worship a great man as God after his death as a matter of hero worship. There were many kings like Lord Rāmacandra, the King of Ayodhyā, but none of them are mentioned as God in the revealed scriptures. To be a good king is not necessarily the qualification for being Lord Rāma, but to be a great personality like Kṛṣṇa is the qualification for being the Personality of Godhead. If we scrutinize the characters who took part in the Battle of Kurukṣetra, we may find that Mahārāja Yudhiṣṭhira was no less a pious king than Lord Rāmacandra, and by character study Mahārāja Yudhiṣṭhira was a better moralist than Lord Kṛṣṇa. Lord Kṛṣṇa asked Mahārāja Yudhiṣṭhira to lie, but Mahārāja Yudhiṣṭhira protested. But that does not mean that Mahārāja Yudhiṣṭhira could be equal to Lord Rāmacandra or Lord Kṛṣṇa. The great authorities have estimated Mahārāja Yudhiṣṭhira to be a pious man, but they have accepted Lord Rāma or Kṛṣṇa as the Personality of Godhead. The Lord is therefore a different identity in all circumstances, and no idea of anthropomorphism can be applied to Him. The Lord is always the Lord, and a common living being can never be equal to Him.