Srimad-Bhagavatam: Canto 6 - Chapter 1 - Verse 4
श्रीशुक उवाचवृत्रविक्रमसंविग्ना: सर्वे देवा: सहर्षिभि: ।तद्वधायार्थयन्निन्द्रं नैच्छद् भीतो बृहद्वधात् ॥ ४ ॥
śrī-śuka uvācavṛtra-vikrama-saṁvignāḥsarve devāḥ saharṣibhiḥtad-vadhāyārthayann indraṁnaicchad bhīto bṛhad-vadhāt
Śrī Śukadeva Gosvāmī answered: When all the great sages and demigods were disturbed by the extraordinary power of Vṛtrāsura, they had assembled to ask Indra to kill him. Indra, however, being afraid of killing a brāhmaṇa, declined their request.