Bhagavad Gita 10.15

स्वयमेवात्मनाऽत्मानं वेत्थ त्वं पुरुषोत्तम।भूतभावन भूतेश देवदेव जगत्पते ॥१०.१५॥

svayamevātmanā’tmānaṃ vettha tvaṃ puruṣottamabhūtabhāvana bhūteśa devadeva jagatpate

Verily, Thou Thyself knowest Thyself by Thyself, O Supreme Person, O source and Lord of all beings, O God of gods, O ruler of the world!

गीता