A saintly person doesn't wish to speak to anyone and everyone, and he is therefore grave and silent. Generally a common man does not need to be advised. Unless one is prepared to take instructions, it is said that a saintly person should not address him, although sometimes, because of great kindness, a saintly person speaks to ordinary men. As for Prahlāda Mahārāja, however, since he was not a common, ordinary man, whatever questions he posed would have to be answered, even by a great and exalted personality. Therefore the saintly brāhmaṇa did not remain silent, but began to answer. These answers, however, were not concocted by him. This is indicated by the words yathā-śrutam, meaning "as I have heard from the authorities." In the paramparā system, when the questions are bona fide the answers are bona fide. No one should attempt to create or manufacture answers. One must refer to the śāstras and give answers according to Vedic understanding. The words yathā-śrutam refer to Vedic knowledge. The Vedas are known as śruti because this knowledge is received from authorities. The statements of the Vedas are known as śruti-pramāṇa. One should quote evidence from the śruti—the Vedas or Vedic literature—and then one's statements will be correct. Otherwise one's words will proceed from mental concoction.
(Srimad Bhagavatam----7:13:23----purport).

My Lord, You are the cause of all causes, but You Yourself have no cause. Therefore You are the wonderful cause of everything. I offer my respectful obeisances unto You, who are the shelter of the Vedic knowledge contained in the śāstras like the Pañcarātras and Vedānta-sūtra, which are Your representations, and who are the source of the paramparā system. Because it is You who can give liberation, You are the only shelter for all transcendentalists. Let me offer my respectful obeisances unto You.
(Srimad Bhagavatam----8:3:15----purport).

All the Vedic mantras, or śruti-mantras, are included in this verse spoken by Lord Brahmā, for Brahmā and his followers, the Brahma-sampradāya, understand the Supreme Personality of Godhead through the paramparā system. We have to gain understanding through the words of our predecessors. There are twelve mahājanas, or authorities, of whom Brahmā is one.
svayambhūr nāradaḥ śambhuḥ
kumāraḥ kapilo manuḥ
prahlādo janako bhīṣmo
balir vaiyāsakir vayam
(S.B.6:3:20)
We belong to the disciplic succession of Brahmā, and therefore we are known as the Brahma-sampradāya. As the demigods follow Lord Brahmā to understand the Supreme Personality of Godhead, we also have to follow the authorities of the paramparā system to understand the Lord.
(Srimad Bhagavatam----8:5:26----purport).

This is the characteristic of a Vaiṣṇava. Para-duḥkha-duḥkhī: a Vaiṣṇava is always unhappy to see the conditioned souls unhappy. Otherwise, he would have no business teaching them how to become happy. In materialistic life, people must certainly engage in activities of animosity. Materialistic life is therefore compared to saṁsāra-dāvānala **, a blazing forest fire that automatically takes place. Lord Śiva and his followers in the paramparā system try to save people from this dangerous condition of materialistic life. This is the duty of devotees following the principles of Lord Śiva and belonging to the Rudra-sampradāya. There are four Vaiṣṇava sampradāyas, and the Rudra-sampradāya is one of them because Lord Śiva (Rudra) is the best of the Vaiṣṇavas (vaiṣṇavānāṁ yathā śambhuḥ). Indeed, as we shall see, Lord Śiva drank all the poison for the benefit of humanity.
(Srimad Bhagavatam----8:7:39----purport).

As stated in Bhagavad-gītā (4.2):
evaṁ paramparā-prāptam
imaṁ rājarṣayo viduḥ
"This supreme science was thus received through the chain of disciplic succession, and the saintly kings understood it in that way." This paramparā system extends from Manu to Ikṣvāku and from Ikṣvāku to his sons and grandsons. The rulers of the world in the line of hierarchy execute the order of the Supreme Personality of Godhead in the paramparā system. Anyone interested in peaceful life must participate in this paramparā system and perform yajñas. As Gauḍīya Vaiṣṇavas in the paramparā system of Śrī Caitanya Mahāprabhu, we must perform saṅkīrtana-yajña all over the world (yajñaiḥ saṅkīrtana-prāyair yajanti hi sumedhasaḥ (S.B.11:5:32). Śrī Caitanya Mahāprabhu is the incarnation of the Supreme Personality of Godhead in this age of Kali, and He will be easily satisfied if the saṅkīrtana movement is spread vigorously all over the world. This will also make people happy without a doubt.
(Srimad Bhagavatam----8:14:6----purport).

Bṛhaspati, the spiritual master of the demigods, informed Indra, "Ordinarily, Bali and his forces could not achieve such strength, but it appears that the brāhmaṇa descendants of Bhṛgu Muni, being pleased with Bali Mahārāja, endowed them with this spiritual power." In other words, Bṛhaspati informed Indra that Bali Mahārāja's prowess was not his own but that of his exalted guru, Śukrācārya. We sing in our daily prayers, yasya prasādād bhagavat-prasādo yasyāprasādān na gatiḥ kuto 'pi **. By the pleasure of the spiritual master, one can get extraordinary power, especially in spiritual advancement. The blessings of the spiritual master are more powerful than one's personal endeavor for such advancement. Narottama dāsa Ṭhākura therefore says:
guru-mukha-padma-vākya, cittete kariyā aikya,
āra nā kariha mane āśā **
Especially for spiritual advancement, one should carry out the bona fide order of the spiritual master. By the paramparā system, one can thus be endowed with the original spiritual power coming from the Supreme Personality of Godhead (evaṁ paramparā-prāptam imaṁ rājarṣayo viduḥ (B.G.4:2).
(Srimad Bhagavatam----8:15:28----purport).

Here the process of devotional service is further explained. Kaśyapa Muni wanted to instruct Aditi in the same process recommended to him by Brahmā for satisfying the Supreme Personality of Godhead. This is valuable. The guru does not manufacture a new process to instruct the disciple. The disciple receives from the guru an authorized process received by the guru from his guru. This is called the system of disciplic succession (evaṁ paramparā-prāptaṁ imaṁ rājarṣayo viduḥ (B.G.4:2.). This is the bona fide Vedic system of receiving the process of devotional service, by which the Supreme Personality of Godhead is pleased. Therefore, to approach a bona fide guru, or spiritual master, is essential. The bona fide spiritual master is he who has received the mercy of his guru, who in turn is bona fide because he has received the mercy of his guru. This is called the paramparā system. Unless one follows this paramparā system, the mantra one receives will be chanted for no purpose. Nowadays there are so many rascal gurus who manufacture their mantras as a process for material advancement, not spiritual advancement. Still, the mantra cannot be successful if it is manufactured. Mantras and the process of devotional service have special power, provided they are received from the authorized person.
(Srimad Bhagavatam----8:16:24----purport).

Lord Śiva is known as Gaṅgā-dhara, or one who carries the water of the Ganges on his head. On Lord Śiva's forehead is the emblem of the half-moon, yet to give supreme respect to the Supreme Personality of Godhead, Lord Śiva placed the water of the Ganges above this emblem. This example should be followed by everyone, or at least by every devotee, because Lord Śiva is one of the mahājanas. Similarly, Mahārāja Bali also later became a mahājana. One mahājana follows another mahājana, and by following the paramparā system of mahājana activities one can become advanced in spiritual consciousness. The water of the Ganges is sanctified because it emanates from the toe of Lord Viṣṇu. Bali Mahārāja washed the lotus feet of Vāmanadeva, and the water with which he did so became equal to the Ganges. Bali Mahārāja, who perfectly knew all religious principles, therefore took that water on his head, following in the footsteps of Lord Śiva.
(Srimad Bhagavatam----8:18:28----purport).

Even though we may not have the fortune to contact the Supreme Lord personally, the Lord's representative is as good as the Lord Himself because such a representative does not say anything unless it is spoken by the Supreme Personality of Godhead. Śrī Caitanya Mahāprabhu therefore gives a definition of guru. Yāre dekha, tāre kaha 'kṛṣṇa'-upadeśa: (CC.2:17:128) the bona fide guru is he who advises his disciples exactly in accordance with the principles spoken by Kṛṣṇa. The bona fide guru is he who has accepted Kṛṣṇa as guru. This is the guru-paramparā system. The original guru is Vyāsadeva because he is the speaker of Bhagavad-gītā and Śrīmad-Bhāgavatam, wherein everything spoken relates to Kṛṣṇa. Therefore guru-pūjā is known as Vyāsa-pūjā. In the final analysis, the original guru is Kṛṣṇa, His disciple is Nārada, whose disciple is Vyāsa, and in this way we gradually come in touch with the guru-paramparā. One cannot become a guru if he does not know what the Personality of Godhead Kṛṣṇa or His incarnation wants. The mission of the guru is the mission of the Supreme Personality of Godhead: to spread Kṛṣṇa consciousness all over the world.
(Srimad Bhagavatam----8:24:48----purport).