अजोऽपि सन्नव्ययात्मा भूतानामीश्वरोऽपि सन्। प्रकृतिं स्वामधिष्ठाय संभवाम्यात्ममायया ॥

ajo ’pi sannavyayātmā bhūtānām īśhvaro ’pi san prakṛitiṁ svām adhiṣhṭhāya sambhavāmyātma-māyayā

Though unborn, the imperishable Self, and also the Lord of all beings, brooding over nature which is Mine own, yet I am born through My own Power.

In plain words: Krishna explains that he is never truly born and never dies, and he is the Lord of all beings. Still, he takes birth in the world by his own divine power, working through nature, which belongs to him.