Srimad-Bhagavatam: Canto 6 - Chapter 1 - Verse 54
Sanskrit:
युष्मभ्यं याचितोऽश्विभ्यां धर्मज्ञोऽङ्गानि दास्यति ।ततस्तैरायुधश्रेष्ठो विश्वकर्मविनिर्मित: ।येन वृत्रशिरो हर्ता मत्तेजउपबृंहित: ॥ ५४ ॥
ITRANS:
yuṣmabhyaṁ yācito ’śvibhyāṁdharma-jño ’ṅgāni dāsyatitatas tair āyudha-śreṣṭhoviśvakarma-vinirmitaḥyena vṛtra-śiro hartāmat-teja-upabṛṁhitaḥ
Translation:
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.