Chandogya Upanishad 3.19

ādityo brahmety ādeśaḥ tasyopavyākhyānam asad evedam agra āsīt tat sad āsīt tat samabhavat tad āṇḍaṃ niravartata tat saṃvatsarasya mātrām aśayata tan nirabhidyata te āṇḍakapāle rajataṃ ca suvarṇaṃ cābhavatām

Âditya (the sun) is Brahman, this is the doctrine, and this is the fuller account of it:— In the beginning this was non-existent. It became existent, it grew. It turned into an egg . The egg lay for the time of a year. The egg broke open. The two halves were one of silver, the other of gold.

tad yad rajataṃ seyaṃ pṛthivī yat suvarṇaṃ sā dyauḥ yaj jarāyu te parvatāḥ yad ulbaṃ ausajh samegho nīhāraḥ yā dhamanayas tā nadyaḥ yad vāsteyam udakaṃ sa samudraḥ

The silver one became this earth, the golden one the sky, the thick membrane (of the white) the mountains, the thin membrane (of the yoke) the mist with the clouds, the small veins the rivers, the fluid the sea.

atha yat tad ajāyata so 'sāv ādityaḥ taṃ jāyamānaṃ ghoṣā ulūlavo 'nūdatiṣṭhant sarvāṇi ca bhūtāni sarve ca kāmāḥ tasmāt tasyodayaṃ prati pratyāyanaṃ prati ghoṣā ulūlavo 'nūttiṣṭhanti sarvāṇi ca bhūtāni sarve ca kāmāḥ

And what was born from it that was Âditya, the sun. When he was born shouts of hurrah arose, and all beings arose, and all things which they desired. Therefore whenever the sun rises and sets, shouts of hurrah arise, and all beings arise, and all things which they desire.

sa ya etam evaṃ vidvān ādityaṃ brahmety upāste abhyāśo ha yad enaṃ sādhavo ghoṣā ā ca gaccheyur upa ca nimreḍeran nimreḍeran

If any one knowing this meditates on the sun as Brahman, pleasant shouts will approach him and will continue, yea, they will continue.