Shatapatha Brahmana 1.9.3.15

1.9.3.15

sa udīkṣate | svayambhūrasi śreṣṭho raśmirityeṣa vai śreṣṭho raśmiryatsūryastasmādāha svayambhūrasi śreṣṭho raśmiriti varcodā asi varco me dehīti tvevāhaṃ bravīmīti ha smāha yājñavalkyastaddhyeva brāhmaṇenaiṣṭhavyaṃ yadbrahmavarcasī syādityuto ha smāhaupoditeya eṣa vāva mahyaṃ gā dāsyati godā gā me dehītyevaṃ yaṃ kāmaṃ kāmayate so 'smai kāmaḥ samṛdhyate

He then looks up to the sun, for that is the final goal, that the safe resort. To that final goal, to that resort he thereby goes: for this reason he looks up to the sun.