Of the six occupational duties of the brahmanas, three are compulsory—namely, worship of the Deity, study of the Vedas and the giving of charity. In exchange, a brahmana should receive charity, and this should be his means of livelihood. A brahmana cannot take up any professional occupational duty for his livelihood. The sastras especially stress that if one claims to be a brahmana, he cannot engage in the service of anyone else; otherwise he at once falls from his position and becomes a sudra. Srila Rupa Gosvami and Sanatana Gosvami belonged to a very respectful family, but because they engaged in the service of Nawab Hussain Shah—not even as ordinary clerks, but as ministers—they were ostracized from brahminical society. Indeed, they became like Mohammedans and even changed their names. Unless a brahmana is very pure, he cannot accept charity from others. Charity should be given to those who are pure. Even if one is born in a family of brahmanas, if one acts as a sudra one cannot accept charity, for this is strictly prohibited. Although the ksatriyas are almost as qualified as the brahmanas, even they cannot accept charity. This is strictly prohibited in this verse by the word apratigraha. What to speak of the lower social orders, even the ksatriyas must not accept charity. The king or government may levy taxes upon the citizens in various ways—by revenue duties, customs duties, realization of fines, and so on—provided the king is able to give full protection to his subjects to assure the security of their life and property. Unless he is able to give protection, he cannot levy taxes. However, a king must not levy any tax upon the brahmanas and the Vaisnavas fully engaged in Krsna consciousness.