BṚHADĀRAṆYAKA UPANISHAD · 1.5.11

तस्यै वाचः पृथिवी शरीरम् ।
ज्योतीरूपम् अयम् अग्निः ।
तद् यावत्य् एव वाक् तावती पृथिवी तावान् अयम् अग्निः ॥

tasyai vācaḥ pṛthivī śarīram ।
jyotīrūpam ayam agniḥ ।
tad yāvaty eva vāk tāvatī pṛthivī tāvān ayam agniḥ ॥

Of that speech (which is the food of Pragâpati) earth is the body, light the form, viz. this fire. And so far as speech extends, so far extends the earth, so far extends fire.

F. Max Müller · The Upanishads, Sacred Books of the East 15 (1884)