Bhagavad Gita · 9.11

अवजानन्ति मां मूढा मानुषीं तनुमाश्रितम्।परं भावमजानन्तो मम भूतमहेश्वरम्॥

avajānanti māṁ mūḍhā mānuṣhīṁ tanum āśhritam paraṁ bhāvam ajānanto mama bhūta-maheśhvaram

The foolish disregard Me when I appear in human form, not knowing My supreme nature as the great Lord of all beings.

— Bhagavad Gita 9.11

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