When the Aśvinī-kumāras beg for Dadhyañca’s body on your behalf, he will surely give it because of affection. Do not doubt this, for Dadhyañca is very experienced in religious understanding. When Dadhyañca awards you his body, Viśvakarmā will prepare a thunderbolt from his bones. This thunderbolt will certainly kill Vṛtrāsura because it will be invested with My power.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
युष्मभ्यं याचितोऽश्विभ्यां धर्मज्ञोऽङ्गानि दास्यति । ततस्तैरायुधश्रेष्ठो विश्वकर्मविनिर्मितः । येन वृत्रशिरो हर्ता मत्तेज उपबृंहितः
yuṣmabhyaṃ yācito'śvibhyāṃ dharmajño'ṅgāni dāsyati | tatastairāyudhaśreṣṭho viśvakarmavinirmitaḥ | yena vṛtraśiro hartā matteja upabṛṃhitaḥ
SB 6.9.54