Dadhyañca’s invincible protective covering known as the Nārāyaṇa-kavaca was given to Tvaṣṭā, who delivered it to his son Viśvarūpa, from whom you have received it. Because of this Nārāyaṇa-kavaca, Dadhīci’s body is now very strong. You should therefore beg him for his body.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
दध्यङ्ङाथर्वणस्त्वष्ट्रे वर्माभेद्यं मदात्मकम् । विश्वरूपाय यत्प्रादात्त्वष्टा यत्त्वमधास्ततः
dadhyaṅṅātharvaṇastvaṣṭre varmābhedyaṃ madātmakam | viśvarūpāya yatprādāttvaṣṭā yattvamadhāstataḥ
SB 6.9.53