The opulence of the demons, who are generally known as the enemies of the demigods, was protected by the talents and tactics of Śukrācārya, but Viśvarūpa, who was most powerful, composed a protective prayer known as the Nārāyaṇa-kavaca. By this intelligent mantra, he took away the opulence of the demons and gave it to Mahendra, the King of heaven.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
सुरद्विषां श्रियं गुप्तामौशनस्यापि विद्यया । आच्छिद्यादान्महेन्द्राय वैष्णव्या विद्यया विभुः
suradviṣāṃ śriyaṃ guptāmauśanasyāpi vidyayā | ācchidyādānmahendrāya vaiṣṇavyā vidyayā vibhuḥ
SB 6.7.39