kīrtau patnyāṁ bṛhacchlokas
As the Lord says in Bhagavad-gītā (4.6):
ajo ’pi sann avyayātmā
bhūtānām īśvaro ’pi san
prakṛtiṁ svām adhiṣṭhāya
“Although I am unborn and My transcendental body never deteriorates, and although I am the Lord of all sentient beings, I still appear in every millennium in My original transcendental form.” When the Supreme Personality of Godhead incarnates, He does not need any help from the external energy, for He appears as He is by His own potency. The spiritual potency is also called māyā. It is said, ato māyāmayaṁ viṣṇuṁ pravadanti manīṣiṇaḥ: the body accepted by the Supreme Personality of Godhead is called māyāmaya. This does not mean that He is formed of the external energy; this māyā refers to His internal potency.