Bhagavad Gita 4.6
अजोऽपि सन्नव्ययात्मा भूतानामीश्वरोऽपि सन्। प्रकृतिं स्वामधिष्ठाय सम्भवाम्यात्ममायया।।4.6।।
ajo'pi sannavyayātmā bhūtānāmīśvaro'pi san| prakṛtiṃ svāmadhiṣṭhāya sambhavāmyātmamāyayā||4.6||
ajo'pi sannavyayatma bhutanamishvaro'pi san prakritim svamadhishthaya sambhavamyatmamayaya4.6
Meaning
Although Krishna is unborn, imperishable, and the Lord of all beings, He manifests through His own divine power (Yoga-maya), controlling His own nature. God's incarnation is an act of grace, not compulsion.
यद्यपि मैं अजन्मा और अविनाशी स्वरूप हूँ और भूतमात्र का ईश्वर हूँ (तथापि) अपनी प्रकृति को अपने अधीन रखकर (अधिष्ठाय) मैं अपनी माया से जन्म लेता हूँ।
This is verse 6 of 42 in Chapter 4 (Jnana Karma Sanyasa Yoga) of the Bhagavad Gita.