BṚHADĀRAṆYAKA UPANISHAD · 4.4.17

यस्मिन् पञ्च पञ्चजना आकाशश् च प्रतिष्ठितः ।
तम् एव मन्य आत्मानं विद्वान् ब्रह्मामृतो ऽमृतम् ॥

yasmin pañca pañcajanā ākāśaś ca pratiṣṭhitaḥ ।
tam eva manya ātmānaṃ vidvān brahmāmṛto ’mṛtam ॥

'He in whom the five beings and the ether rest, him alone I believe to be the Self,--I who know, believe him to be Brahman; I who am immortal, believe him to be immortal.