Bhagavad Gita · 10.42

अथवा बहुनैतेन किं ज्ञातेन तवार्जुन।विष्टभ्याहमिदं कृत्स्नमेकांशेन स्थितो जगत्॥

atha vā bahunaitena kiṁ jñātena tavārjuna viṣhṭabhyāham idaṁ kṛitsnam ekāṁśhena sthito jagat

But what need is there, Arjuna, for all this detailed knowledge? I support this entire cosmos with a single fragment of myself, and I remain.

— Bhagavad Gita 10.42

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