Bhagavad Gita · 14.3

मम योनिर्महद्ब्रह्म तस्मिन्गर्भं दधाम्यहम्।सम्भवः सर्वभूतानां ततो भवति भारत॥

mama yonir mahad brahma tasmin garbhaṁ dadhāmy aham sambhavaḥ sarva-bhūtānāṁ tato bhavati bhārata

The great material nature is my womb. In it I place the seed of consciousness. From this arises the birth of all beings, O Arjuna.

— Bhagavad Gita 14.3

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)