Srimad Bhagavatam Canto 04, Chapter 02, Text 27

SB 4.2.27

tasyaivam vadatah sapam
srutva dvija-kulaya vai
bhrguh pratyasrjac chapam
brahma-dandam duratyayam
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
When all the hereditary brahmanas were thus cursed by Nandisvara, the sage Bhrgu, as a reaction, condemned the followers of Lord Siva with this very strong brahminical curse.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
The word duratyaya is particularly used in reference to a brahmadanda, or curse by a brahmana. A curse by a brahmana is very strong; therefore it is called duratyaya, or insurmountable. As the Lord states in Bhagavad-gita, the stringent laws of nature are insurmountable; similarly, if a curse is uttered by a brahmana, that curse is also insurmountable. But Bhagavad-gita also says that the curses or benedictions of the material world are, after all, material creations. The Caitanya-caritamrta confirms that that which is accepted in this material world to be a benediction and that which is taken to be a curse are both on the same platform because they are material. To get out of this material contamination, one should take shelter of the Supreme Personality of Godhead, as recommended in Bhagavad-gita (7.14): mam eva ye prapadyante mayam etam taranti te. The best path is to transcend all material curses and benedictions and take shelter of the Supreme Lord, Krsna, and remain in a transcendental position. Persons who have taken shelter of Krsna are always peaceful; they are never cursed by anyone, nor do they attempt to curse anyone. That is a transcendental position.
Srimad Bhagavatam Canto 04, Chapter 02, Text 26
Srimad Bhagavatam Canto 04, Chapter 02, Text 28