Chandogya Upanishad 8.8.3

8.8.3

tau hocatur yathaivedam āvāṃ bhagavaḥ sādhvalaṃkṛtau suvasanau pariṣkṛtau sva evam evemau bhagavaḥ sādhvallaṃkṛtau suvasanau pariṣkṛtāv iti \
eṣa ātmeti hovāca \
etad amṛtam abhayam etad brahmeti \
tau ha śāntahṛdayau pravavrajatuḥ \\808.3\

3. Then the two said: ‘Just as we ourselves are here, Sir, well-ornamented, well-dressed, adorned—so there, Sir, well-ornamented, well-dressed, adorned.’ ‘That is the Self,’ said he. ‘That is the immortal, the fearless. That is Brahma.’ Then with tranquil heart (śānta-hṛdaya) the two went forth.