This relationship of spiritual master and student . . . the student is called śiṣya. Śiṣya, the Sanskrit word śiṣya, this word comes from the root śas. Śas means ruling. From śas, the śāstra. Śāstra means authoritative books. They have been derived. And śastra. Śastra means weapons, armaments. That is called śastra. Just like sword, guns, they are called śastra. These two things are rulings. The state has got law books, authoritative books, and one who does not obey the law books, then the next word is gun and sword. This, these two words means to accept authority.
So śiṣya means one who accepts the authority of the spiritual master. He voluntarily accepts the rulings or the punishment of the spiritual master. That is called śiṣya. One voluntarily agrees to the spiritual master . . . this initiation is going on. This is the beginning of voluntary acceptance of the spiritual master. That means he agrees that he will abide by the orders of the spiritual master. This is called acceptance of spiritual master. Śiṣya. Śiṣya means voluntarily accepting the ruling. Everyone is free. If I give you some ruling, why should you accept it? Therefore this formal initiation ceremony is performed. He promises, "My dear sir, I shall abide by your order."
So Kṛṣṇa was accepted by Arjuna as spiritual master just to teach him what is the actual duty in that war field. So at that time the first śiṣya, śāsana, ruling, He chastised Arjuna by these words, "My dear Arjuna, you are talking just like a very learned man, but no learned man talks like this." That means "You are a fool." He very politely said that, "You are talking with Me as if you are very learned man, but your subject matter is so third class that no learned man takes this subject matter very seriously." What is that? Bodily conception of life. "You are talking just like a very learned man, but your center of activity is the body. So this is not a learn . . . symptom of a learned man."
So if we take this crucial test of learning, we shall find hardly a learned man in this world, hardly one man, because everyone is absorbed in this bodily conception of life. All their ideas—this nationality, humanity, this duty, that duty, all—everything on this. Yasyātma-buddhiḥ kuṇape tri-dhātuke (SB 10.84.13).
They are accepting this bag of skin and bones as self. You see? This is a bag made of skin and bone, and this . . . is spirit soul so cheap thing that it is a bag of skin and bone and some stools and urine, combination? That is nonsense. So hardly you'll find any sane man or any learned man in this world. You see?
So first teaching is that, "You are not this body." That is the beginning of Kṛṣṇa's teaching.