The Personality of Godhead, the all-compassionate controller of both the spiritual and material creations, is unborn, but when there is friction between His peaceful devotees and persons who are in the material modes of nature, He takes birth just like fire, accompanied by the mahat-tattva.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
स्वशान्तरूपेष्वितरैः स्वरूपै- रभ्यर्द्यमानेष्वनुकम्पितात्मा । परावरेशो महदंशयुक्तो ह्यजोऽपि जातो भगवान् यथाग्निः
svaśāntarūpeṣvitaraiḥ svarūpai- rabhyardyamāneṣvanukampitātmā | parāvareśo mahadaṃśayukto hyajo'pi jāto bhagavān yathāgniḥ
SB 3.2.15