Here says, śiṣyas te 'ham (BG 2.7): "Now I am accepting You as my guru. I become Your śiṣya." Śiṣya means "Whatever you'll say, I'll accept." That is śiṣya. The śiṣya word comes from śas-dhātu. Śas-dhātu. Śāstra. Śastra. Śāsana. Śiṣya. These are from the same root. Śas-dhātu. Śas-dhātu means rule, ruling. So we can rule in various way. We can be ruled, becoming a śiṣya of a proper guru. That is śas-dhātu. Or we can be ruled by śastra, weapon. Just like king has got weapon. If you don't follow the king's instruction or government instruction, then there is police force, military force. That is śastra. And there is śāstra also. Śāstra means book, scripture, just like Bhagavad-gītā. Everything is there. So we must be ruled, either by śastra, śāstra or guru. Or becoming śiṣya. Therefore it is said, śiṣyas te 'ham (BG 2.7): "I become voluntarily . . . I surrender unto You." "Now you become śiṣya. What is the proof that you have become My śiṣya?" Śādhi māṁ tvāṁ prapannam: "Now I am fully surrendered." Prapannam.
So this knowledge required, how to find out real guru and how to surrender unto Him. The guru does not mean that I keep a guru, so, as order-supplier: "My dear guru, I am suffering from this. Can you give me some medicine?" "Yes, yes. Take this medicine." "Yes." Not that guru. If you are suffering from some disease, you go to a physician. It is not guru's business to give you some medicine. A guru's business is to give you Kṛṣṇa. Kṛṣṇa sei tomāra, kṛṣṇa dīte pāra (Bhajana-Lālasā, Song 7). A Vaiṣṇava is praying, guru: "Sir, you are devotee of Kṛṣṇa. You can give me Kṛṣṇa if you like." This is the position of śiṣya. Guru's business is how to give you Kṛṣṇa, not any material things. For material things, there are so many institution. But if you want Kṛṣṇa, then guru's required.