MI.Upanishad 1.03

अथातो रेतसः सृष्टिः। प्रजापते रेतो देवाः। देवानां रेतो वर्षम्। वर्षस्य रेत ओषधयः। ओषधीनां रेतोऽन्नं अन्नस्य रेतो रेतः रेतसो रेतः प्रजाः प्रजानां रेतो हृदयं हृदयस्य रेतो मनः मनसो रेतो वाग् वाचो रेतः कर्म। तदिदं कर्म कृतम् । अयं पुरुषो ब्रह्मणो लोकः। स इरामयः। यद्धीरामयास्तस्मात् हिरण्मयः। हिरण्मयो ह वा अमुष्मिं ल्लोके सम्भवति हिरण्मयः सर्वेभ्यो भूतेभ्यो ददृशे य एवं वेद ॥३॥

Now, therefore, the creation of the generative seed: the gods are Prajāpati's seed; rain is the seed of the gods; plants are the seed of rain; food is the seed of plants; semen is the seed of food; offspring are the seed of semen; the heart is the seed of offspring; mind is the seed of the heart; speech is the seed of mind; action is the seed of speech. This action has been performed. This person is the world of Brahman. He consists of nourishment. Since he indeed consists of nourishment, he is therefore golden. Whoever knows thus comes into being golden in that world; golden, he is visible to all beings. (3)

MI.Bāshya 1.03

स एष भगवान् विष्णुः प्रजापतिरितीरितः। तस्मात् जाताः सर्वदेवा ब्रह्माद्यास्तेभ्य एव च॥

This very Lord Viṣṇu is called Prajāpati. From him were born all the gods beginning with Brahmā, and from them indeed as well.

वृष्टिः सञ्जायते तस्याः सर्वा ओषधयोऽभवन्। ओषधीभ्योऽन्नमन्नाच्च रेतो रेतस एव च॥

From that, rain is produced, and all plants came into being. From plants came food, from food came seed, and from seed itself.

सर्वाः प्रजाः प्रजायन्ते सङ्कल्पो हृदयाभिधः। प्रजाभ्यो जायते तस्माद् विकल्पाख्यं मनस्तथा॥

All beings are born; resolve is called the heart. From those beings, likewise, the mind called differentiation is born.

विकल्पाद् वाक् प्रचारश्च वाचा नामादिवेदनात्। कर्म सञ्जायते तस्मात् कर्मणश्च जगत् पुनः॥

From conceptual differentiation arise speech and its expression. Through speech, from the cognition of names and the like, action is produced; and from action, the world arises again.

कर्माभिमान्ययं जीवः परस्य ब्रह्मणो हरेः। आवासस्थानमुद्दिष्टो विशेषात् स इरामयः॥

This jīva, identified with action, is said to be the abode of the supreme Brahman, Hari. Specifically, he is composed of irā.

इच्छानुरूपं तु सुखं इरेत्येव प्रकीर्तितम्। इच्छानन्दप्रभूतत्वात् स एव च हिरण्मयः॥

But happiness according to desire is indeed proclaimed as Irā. And because of being abundant in desire and bliss, he indeed is Hiraṇmaya.

हिरुक् सुखं हिरण्यं स्याद् बाह्यानन्दात् पृथग् यतः। आधिक्यार्थे मयड् यस्माद् अधिकानन्दरूपकः॥

Hiraṇya means a happiness set apart, because it is distinct from external pleasure. Since the suffix mayaḍ denotes abundance, it is characterized as the form of superior bliss.

उत्सृज्य कर्मजं रूपं निजानन्दैकरूपकः। एवं नारायणं जानन् सर्वलोकैककारणम्॥ तल्लोके दृश्यते भूतैर्मुक्तैरानन्दरूपकः॥

Having cast off the form produced by karma and being of the nature of his own bliss alone, he knows Nārāyaṇa as the sole cause of all worlds. In that world, he is seen by liberated beings as one whose nature is bliss.