Verse 1.6.6

अथ यदेवैतदादित्यस्य शुक्लं भाः सैव साथ यन्नीलं परः कृष्णं तदमस्तत्सामाथ य एषोऽन्तरादित्ये हिरण्मयः पुरुषो दृश्यते हिरण्यश्मश्रुर्हिरण्यकेश आप्रणस्वात्सर्व एव सुवर्णः ॥ १.६.६ ॥

atha yadevaitadādityasya śuklaṃ bhāḥ saiva sātha yannīlaṃ paraḥ kṛṣṇaṃ tadamastatsāmātha ya eṣo'ntarāditye hiraṇmayaḥ puruṣo dṛśyate hiraṇyaśmaśrurhiraṇyakeśa āpraṇasvātsarva eva suvarṇaḥ || 1.6.6 ||

6. Then, [worship of the effulgent being in the sun]: The white glow of the sun is sā, and the dark bluish-black glow is ama. These two together make up the word Sāma. There is a deity within the orb of the sun, who is seen by yogīs. His whole body glitters like gold, even to his toe-nails. He has a bright golden beard and bright golden hair.

Word-for-word explanation:

Atha, then; yat eva etat ādityasya śuklam bhāḥ, that which is this white glow of the sun; sā eva sā, that is the ‘sā’ [of Sāma]; atha yat nīlam paraḥ kṛṣṇam, and that which is the deep black glow; tat amaḥ, that is ‘ama’; tat sāma, [when they are put together] that is Sāma; atha antarāditye, again inside the orb of the sun; yāḥ eṣaḥ hiraṇmayaḥ, there is a bright figure; hiraṇyaśmaśruḥ, bright gold beard; hiraṇyakeśaḥ puruṣaḥ dṛśyate, the person with bright gold hair seen [by the yogīs]; āpraṇakhāt sarva eva suvarṇaḥ, bright gold all over the body, including even his nails.

Commentary:

The sun is partly white and partly dark. These colours together make up ‘Sāma.’

The Upaniṣad does not mean to say that the sun is made of gold, and neither is the person in the orb of the sun. This is not to be taken literally.

What is meant here is that the person in the sun is brilliant—brilliant in terms of moral and spiritual qualities. The word gold refers to his character and not to the colour of his skin.

The word puruṣa means ‘one who covers the whole