CHĀNDOGYA UPANISHAD · 1.11.7

आदित्य इति होवाच ।
सर्वाणि ह वा इमानि भूतान्य् आदित्यम् उच्चैः सन्तं गायन्ति ।
सैषा देवतोद्गीथम् अन्वायत्ता ।
तां चेद् अविद्वान् उदगास्यो मूर्धा ते व्यपतिष्यत् तथोक्तस्य मयेति ॥

āditya iti hovāca ।
sarvāṇi ha vā imāni bhūtāny ādityam uccaiḥ santaṃ gāyanti ।
saiṣā devatodgītham anvāyattā ।
tāṃ ced avidvān udagāsyo mūrdhā te vyapatiṣyat tathoktasya mayeti ॥

He said: 'The sun (âditya). For all these beings praise the sun when it stands on high. This is the deity belonging to the udgîtha. If, without knowing that deity, you had sung out your hymns, your head would have fallen off, after you had been warned by me.'

F. Max Müller · The Upanishads, Sacred Books of the East 1 (1879)