Bhagavad Gita 13.4
What is called Matter, of what it is composed, whence it came, and why it changes, what the Self is, and what its power - this I will now briefly set forth.
तत्क्षेत्रं यच्च यादृक् च यद्विकारि यतश्च यत्।स च यो यत्प्रभावश्च तत्समासेन मे श्रृणु॥tatkṣetraṃ yacca yādṛk ca yadvikāri yataśca yat|sa ca yo yatprabhāvaśca tatsamāsena me śrṛṇu||
English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).