Bhagavad Gita 10.42

But what is the use of all these details to you, O Arjuna? I sustain this universe with only a small part of Myself.

अथवा बहुनैतेन किं ज्ञातेन तवार्जुन।
विष्टभ्याहमिदं कृत्स्नमेकांशेन स्थितो जगत्॥

athavā bahunaitena kiṃ jñātena tavārjuna|
viṣṭabhyāhamidaṃ kṛtsnamekāṃśena sthito jagat||

English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).