mama yonirmahadbrahma tasmin garbhaṃ dadhāmyaham |saṃbhavaḥ sarvabhūtānāṃ tato bhavati bhārata ||
The great Brahman is my womb; in it I place the seed. From that, O descendant of Bharata, the birth of all beings comes about.
Explanation
Krishna explains to Arjuna how the world comes to be. Here "great Brahman" (mahad brahma) is usually understood as the vast primal nature (prakṛti), the womb-like source of matter, and Krishna is the one who places the seed of life in it. Commentators differ on details: some take this Brahman as the unmanifest material nature, others as a broader cosmic principle, but all agree that creation arises from Krishna's will working through it.