Vivasvān, his son was Manu, and Manu, the father of the mankind, his son was the king Ikṣvāku, and King Ikṣvāku was the king of this earthly planet and, from him, this paramparā system or disciplic succession is coming down. But it has broken down. The Lord said to Arjuna, sa kāleneha yogo naṣṭaḥ parantapa: "In course of time, that disciplic succession has now broken. Therefore I make again you as My disciple."
He has already accepted Kṛṣṇa as spiritual master in the Second Chapter. In the beginning of the Second Chapter Kṛṣṇa said, śiṣyas te 'haṁ śādhi māṁ prapannam (BG 2.7): "So long we are talking as friends, but now I surrender myself as my spiritual master, Kṛṣṇa." So therefore Kṛṣṇa was speaking to Arjuna on the platform of spiritual master.
So we should note it that the spiritual . . . perfect spiritual master is Kṛṣṇa. And anyone who is following the principles, as Kṛṣṇa says, he's also representative of Kṛṣṇa. And the teacher is Kṛṣṇa and the Arjuna is the student. Similarly, as the spiritual master is the representative of Kṛṣṇa, similarly a student must be also the representative of Arjuna. Then Bhagavad-gītā discussion will be nice.
So what is that, Arjuna's position? You'll find in this chapter which we are now just beginning. He said, sarvam etad ṛtaṁ manye yad vadasi keśava (BG 10.14): "My dear Kṛṣṇa, whatever You are speaking, I accept. I accept it." So that should be the process of understanding Kṛṣṇa, er, Bhagavad-gītā. Not that "I don't like this. So I'll reject this portion. I like this portion, therefore I accept it." This sort of studying Bhagavad-gītā is useless, nonsense. Sarvam etad ṛtaṁ manye: "Whatever You have said, I accept it." That is stated.
Similarly, a teacher of Bhagavad-gītā should be a representative of Kṛṣṇa. Representative of Kṛṣṇa means a confidential devotee, unalloyed devotee of Kṛṣṇa. The same thing. He also accepted Kṛṣṇa as his . . . the student also should be like that.