Bhagavad Gita · 11.31

आख्याहि मे को भवानुग्ररूपोनमोऽस्तु ते देववर प्रसीद।विज्ञातुमिच्छामि भवन्तमाद्यंन हि प्रजानामि तव प्रवृत्तिम्॥

ākhyāhi me ko bhavān ugra-rūpo namo 'stu te deva-vara prasīda vijñātum ichchhāmi bhavantam ādyaṁ na hi prajānāmi tava pravṛttim

Tell me who you are in this fierce form! I bow to you, O greatest of gods, be gracious. I wish to know you, the primeval one, for I do not understand your mission.

— Bhagavad Gita 11.31

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)