SB 6.9.53
dadhyann atharvanas tvastre
varmabhedyam mad-atmakam
visvarupaya yat pradat
tvasta yat tvam adhas tatah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Dadhyañca’s invincible protective covering known as the Narayana-kavaca was given to Tvasta, who delivered it to his son Visvarupa, from whom you have received it. Because of this Narayana-kavaca, Dadhici’s body is now very strong. You should therefore beg him for his body.