Bhagavad Gita : अध्याय 14 का श्लोक 3
मम योनिर्महद्ब्रह्म तस्मिन्गर्भं दधाम्यहम् ।
सम्भवः सर्वभूतानां ततो भवति भारत ॥
भावार्थ : हे अर्जुन! मेरी महत्-ब्रह्मरूप मूल-प्रकृति सम्पूर्ण भूतों की योनि है अर्थात गर्भाधान का स्थान है और मैं उस योनि में चेतन समुदायरूप गर्भ को स्थापन करता हूँ। उस जड़-चेतन के संयोग से सब भूतों की उत्पति होती है॥3॥
The total material substance, called Brahman, is the source of birth, and it is that Brahman that I impregnate, making possible the births of all living beings, O son of Bharata.
This is an explanation of the world: everything that takes place is due to the combination of kṣetra and kṣetrajña, the body and the spirit soul. This combination of material nature and the living entity is made possible by the Supreme God Himself. The mahat-tattva is the total cause of the total cosmic manifestation, and because in the total substance of the material cause there are three modes of nature, it is sometimes called Brahman. The Supreme Personality impregnates that total substance, and thus innumerable universes become possible. This total material substance, the mahat-tattva, is described as Brahman in the Vedic literature: tasmād etad brahma nāma-rūpam annaṁ ca jāyate. Into that Brahman the seeds of the living entities are impregnated by the Supreme Person. The twenty-four elements, beginning from earth, water, fire and air, are all material energy, called Mahā-brahman, or the great Brahman, the material nature. As is explained in the Seventh Chapter, beyond this there is another, superior nature-the living entity. In material nature the superior nature is mixed by the will of the Supreme Personality of Godhead, and thereafter all living entities are born of this material nature.
The scorpion lays its eggs in piles of rice, and sometimes it is said that the scorpion is born out of rice. But the rice is not the cause of the scorpion. Actually, the eggs were laid by the mother. Similarly, material nature is not the cause of the birth of the living entities. The seed is given by the Supreme Personality of Godhead, and they only seem to come out as products of material nature. Thus every living entity, according to his past activities, has a different body, created by this material nature, and the entity can enjoy or suffer according to his past deeds. The Lord is the cause of all the manifestations of living entities in this material world.