MĀṆḌŪKYA UPANISHAD · 2

सर्वं ह्येतद् ब्रह्मायमात्मा ब्रह्म सोऽयमात्मा चतुष्पात् ॥ २॥

sarvaṃ hyetad brahmāyamātmā brahma so’yamātmā catuṣpāt ॥ 2॥

All this Universe is the Eternal Brahman, this Self is the Eternal, and the Self is fourfold.