تاریخ استان ایران
Conclusion –The Perfection of Benunciation
845
PURPORTE
Vyāsa was the spiritual master of Sañjaya, and Sañjaya admits that it was by his mercy that he could understand the Supreme Personality of Godhead. This means that one has to understand Kṛṣṇa not directly but through the medium of the spiritual master. The spiritual master is the transparent medium, although it is true that the experience is direct. This is the mystery of the disciplic succession. When the spiritual master is bona fide, then one can hear  Bhagavad-gītā  directly, as Arjuna heard it. There are many mystics and  yogīs  all over the world, but Kṛṣṇa is the master of all  yoga  systems. Kṛṣṇa's instruction is explicitly stated in  Bhagavad-gītā —surrender unto Kṛṣṇa. One who does so is the topmost  yogī . This is confirmed in the last verse of the Sixth Chapter.  Yoginām api sarveṣām .
Nārada is the direct disciple of Kṛṣṇa and the spiritual master of Vyāsa. Therefore Vyāsa is as bona fide as Arjuna because he comes in the disciplic succession, and Sañjaya is the direct disciple of Vyāsa. Therefore by the grace of Vyāsa, his senses were purified, and he could see and hear Kṛṣṇa directly. One who directly hears Kṛṣṇa can understand this confidential knowledge. If one does not come to the disciplic succession, he cannot hear Kṛṣṇa; therefore his knowledge is always imperfect, at least as far as understanding  Bhagavad-gītā  is concerned.
In  Bhagavad-gītā , all the  yoga  systems,  karma-yoga ,  jñāna-yoga  and  bhakti-yoga , are explained. Kṛṣṇa is the master of all such mysticism. It is to be understood, however, that as Arjuna was fortunate enough to understand Kṛṣṇa directly, similarly, by the grace of Vyāsa, Sañjaya was also able to hear Kṛṣṇa directly. Actually there is no difference in hearing directly from Kṛṣṇa or hearing directly from Kṛṣṇa via a bona fide spiritual master like Vyāsa. The spiritual master is the representative of Vyāsadeva also. According to the Vedic system, on the birthday of the spiritual master, the disciples conduct the ceremony called  Vyāsa-pūjā .
TEXT 76
राजन्संस्मृत्य संस्मृत्य संवादमिममद्भुतम् । केशवार्जुनयोः पुण्यं हृष्यामि च मुहुर्मुहुः ॥ ७६ ॥
rājan saṁsmṛtya saṁsmṛtya saṁvādam imam adbhutam keśavārjunayoḥ puṇyaṁ hṛṣyāmi ca muhur muhuḥ