SB 4.2.26
sarva-bhaksa dvija vrttyai
dhrta-vidya-tapo-vratah
vitta-dehendriyarama
yacaka vicarantv iha
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
These brahmanas take to education, austerity and vows only for the purpose of maintaining the body. They shall be devoid of discrimination between what to eat and what not to eat. They will acquire money, begging from door to door, simply for the satisfaction of the body.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The third curse inflicted by Nandisvara on the brahmanas who supported Daksa is completely functioning in the Age of Kali. The so-called brahmanas are no longer interested in understanding the nature of the Supreme Brahman, although a brahmana means one who has attained knowledge about Brahman. In the Vedanta-sutra also it is stated, athato brahma-jijñasa: this human form of life is meant for realization of the Supreme Brahman, the Absolute Truth, or, in other words, human life is meant for one’s elevation to the post of a brahmana. Unfortunately the modern brahmanas, or so-called brahmanas who come in originally brahminical families, have left their own occupational duties, but they do not allow others to occupy the posts of brahmanas. The qualifications for brahmanas are described in the scriptures, in Srimad-Bhagavatam, Bhagavad-gita and all other Vedic literatures. Brahmana is not a hereditary title or position. If someone from a non-brahmana family (for example, one born in a family of sudras) tries to become a brahmana by being properly qualified under the instruction of a bona fide spiritual master, these so-called brahmanas will object. Such brahmanas, having been cursed by Nandisvara, are actually in a position where they have no discrimination between eatables and noneatables and simply live to maintain the perishable material body and its family. Such fallen conditioned souls are not worthy to be called brahmanas, but in Kali-yuga they claim to be brahmanas, and if a person actually tries to attain the brahminical qualifications, they try to hinder his progress. This is the situation in the present age. Caitanya Mahaprabhu condemned this principle very strongly. During His conversation with Ramananda Raya, He said that regardless of whether a person is born in a brahmana family or sudra family, regardless of whether he is a householder or a sannyasi, if he knows the science of Krsna he must be a spiritual master. Caitanya Mahaprabhu had many so-called sudra disciples, like Haridasa Thakura and Ramananda Raya. Even the Gosvamis, who were principal students of Lord Caitanya, were also ostracized from brahmana society, but Caitanya Mahaprabhu, by His grace, made them first-class Vaisnavas.