Guru means whatever instruction he'll give, we have to accept without any argument. Vedic knowledge is like that. You cannot interpret. As it is, you have to accept. Similarly guru's word also you have to accept. No argument. That is Vedic knowledge. That is the Vedic system. This example we have given many times: Just like this cow dung. Cow dung is the stool of an animal. So the stool of an animal is most impure thing. As soon as you touch, even your own stool . . . You may be very learned scholar or devotee, but that does not meant you can touch your own stool and remain purified. No. Immediately you have to take bath. Even his own, what to speak of others'. But in the Vedic instruction we see that the cow dung, it is the stool of an animal also, lower animal than the man, and it is pure, it is said. So you have to accept pure. No argument that "Such stool is impure. Even my spiritual master's stool is also impure. How is that that animal cow dung is pure?" But because it is in the Vedas it is said pure, you have to accept. Similarly, the conchshell, it is the bone of an animal. The bone, if you touch any dead body's bone, you'll have to take, immediately, purify. But that, this bone is placed in the Deity room. We are daily blowing the conchshell—because the Vedic instruction. So there is no argument. If you accept Vedic instruction, you have to accept it as it is.
Therefore we are protesting to all these rascals who are making interpretation of Bhagavad-gītā, "You rascals, you cannot do anything. You have to accept Kṛṣṇa's word. That is Vedic knowledge. And if, you rascal, if you interpret, then you are lost and everything is lost." Yogo naṣṭaḥ parantapa.