Brahma-bandhu, or kṣatra-bandhu, a person born in the family of a brāhmaṇa but has no brāhmaṇa qualification, he is called brahma-bandhu, "friend of a brāhmaṇa." Bandhu means friend. Just a . . . A person, a man, his father is high-court judge. So there is no harm that he belongs to the family of such and such high-court judge—but that does not mean he is high-court judge. It should be noted. That is the difference, brāhmaṇa and brahma-bandhu. Brāhmaṇa means guṇa-karma-vibhāgaśaḥ (BG 4.13). He must have the quality: śamo damaḥ śaucaṁ titikṣā ārjavam, jñānaṁ vijñānam āstikyaṁ brahma-karma svabhāva-jam (BG 18.42). He must be self-controlled, controlling the mind and the senses. Then very clean, śaucam. Satyaṁ śaucam. Then titikṣā, tolerant; ārjavam, very simple, no duplicity. Simple, ārjavam. Jñānam, full knowledge; vijñānam, knowledge applied in practical life. This is vijñānam. Just like we call science. Science means to know the things correctly, and by practical experiment to understand the things correctly, that is vijñānam. Jñānam means theoretical knowledge, and vijñānam means practical application of the knowledge. Simply if I know, "This is the qualification of brāhmaṇa," but there is no practical application, that will not do. One must pass the engineering examination and work as engineer; then he's called an engineer. One has passed the law examination and is practicing in the court, then he's lawyer. Two things required. Similarly, all these varṇa-vibhāga, division of varṇas . . . Guṇa-karma-vibhāgaśaḥ. Guṇa means he must have the necessary quality, at the same time he must work with that quality. Then he is . . . Cātur-varṇyaṁ mayā sṛṣṭaṁ guṇa-karma-vibhāgaśaḥ (BG 4.13).
So here, Aśvatthāmā, he's born of a brāhmaṇa father, but his work has been proved just like a butcher. So therefore he is called brahma-bandhu. He's called not a brāhmaṇa: brahma-bandhu. Brahma-bandhoḥ śira ātatāyinaḥ. Ātatāyinaḥ, aggressor. A brāhmaṇa does not require to kill a person with weapon. No. That is kṣatriya's business. If one is actually a brāhmaṇa—of course, in the Kali-yuga such brāhmaṇa is not to be found—his simply curse is sufficient to kill a man. If a brāhmaṇa curses somebody . . . Just like Mahārāja Parīkṣit, he was cursed by a brāhmaṇa's son. Means not fully brāhmaṇa, grown-up. A child, a boy twelve years old, he cursed Parīkṣit Mahārāja that "Within seven days you'll be bitten by a serpent," and it came to be true. So brāhmaṇa does not require any sword or any arrow to kill a man. His very word is sufficient. Therefore when somebody was to be killed, the brāhmaṇa would bring him to the kṣatriya—not killing himself by weapon. Just like Viśvāmitra, he wanted to kill one rākṣasī, so he came to Mahārāja Daśaratha, kṣatriya, to do the business of killing. There are so many . . . That is śāstric evidences.
So here, a brahma-bandhu . . . Aśvatthāmā was born of a brāhmaṇa, Droṇācārya, but he killed the five sons of Draupadī most abominably, when they were sleeping. So what to speak of brāhmaṇa, he's less than a kṣatriya even, because a kṣatriya also do not kill anybody while one is sleeping. A kṣatriya challenges, offers him weapon, fights, and then one of them is killed. That is . . . So here it is brahma-bandhoḥ ātatāyinaḥ. Ātatāyinaḥ, aggressor. Anyone who kidnaps one's wife is called aggressor. One who sets fire in your house, he's aggressor. One who is coming to kill you with weapon, he's aggressor. In this way there is a list of aggression. So aggressor can be killed immediately, if somebody is aggressor. There is no sin in killing aggressor. Enemy who sets fire to the house, administers poison, attacks all of a sudden with deadly weapon, plunders wealth or usurps agricultural field or entices one's wife is called an aggressor. Everything . . . This is Vedic knowledge. Everything has got definition.