01What is woven on what
Her first question (Brihadaranyaka 3.6) climbs a ladder. Everything here is woven on water, warp and woof; on what is water woven? On air. On what is air woven? She takes him up through the worlds of the gandharvas, sun, moon, stars, devas, Indra and Prajapati to the worlds of Brahman. There Yajnavalkya stops her: ‘Gargi, do not ask too much, or your head will fall off.’ She sat down.
02Two arrows
She rose again (3.8), this time asking the assembly’s leave, and said she would put two questions to him like a warrior of Kashi or Videha fitting two arrows to a bow. What lies above the sky and below the earth, that which was, is and will be: on what is that woven? On space, he said. And on what is space woven? He answered: on the Akshara, the Imperishable, by whose command sun and moon hold their places. Gargi then told the brahmins that none of them would ever beat him in discussion of Brahman.
“Venerable brahmins, count yourselves lucky if you get away from him with a bow. None of you will ever defeat him in a debate about Brahman.”
Brihadaranyaka Upanishad 3.8.12