Bhagavad Gita Chapter 15.17
uttamaḥ puruṣas tv anyaḥ
paramātmety udāhṛtaḥ
yo loka-trayam āviśya
bibharty avyaya īśvaraḥ
Translation
Besides these two, there is the greatest living personality, the Supreme Soul, the imperishable Lord Himself, who has entered the three worlds and is maintaining them.