SB 6.9.54

yuṣmabhyaṁ yācito ’śvibhyāṁ
 dharma-jño ’ṅgāni dāsyati
tatas tair āyudha-śreṣṭho
 viśvakarma-vinirmitaḥ
yena vṛtra-śiro hartā
 mat-teja-upabṛṁhitaḥ
Synonyms: 
yuṣmabhyam — for all of you; yācitaḥ — being asked; aśvibhyām — by the Aśvinī-kumāras; dharma-jñaḥ — Dadhīci, who knows the principles of religion; aṅgāni — his limbs; dāsyati — will give; tataḥ — after that; taiḥ — by those bones; āyudha — of weapons; śreṣṭhaḥ — the most powerful (the thunderbolt); viśvakarma-vinirmitaḥ — manufactured by Viśvakarmā; yena — by which; vṛtra-śiraḥ — the head of Vṛtrāsura; hartā — will be taken away; mat-tejaḥ — by My strength; upabṛṁhitaḥ — increased.
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.