Mundaka 1.09
यः सर्वज्ञः स सर्ववित् यस्य ज्ञानमयं तपः। तस्मादेतत् ब्रह्म नाम रूपमन्नं च जायते ॥९॥
yaḥ sarvajñaḥ sa sarvavit yasya jñānamayaṃ tapaḥ। tasmādetat brahma nāma rūpamannaṃ ca jāyate ॥9॥
[यः (yaḥ) - who; सर्वज्ञः (sarvajñaḥ) - omniscient; स (sa) - he; सर्ववित् (sarvavit) - all-knowing; यस्य (yasya) - whose; ज्ञानमयं (jñānamayaṃ) - consisting of knowledge; तपः (tapaḥ) - austerity; तस्मात् (tasmāt) - therefore; एतत् (etat) - this; ब्रह्म (brahma) - Brahma; नाम (nāma) - name; रूपम् (rūpam) - form; अन्नम् (annam) - food; च (ca) - and; जायते (jāyate) - is born;]
The omniscient and all-knowing one, whose austerity is made of knowledge, from him arise Lord Brahma, name, form, and food.
Bhāshya 1.09
The 'brahma' referred to in the context is the four-faced Lord Brahma.
एतद्ब्रह्म चतुर्मुखः॥
etadbrahma caturmukhaḥ॥
[एतत् (etat) - this; ब्रह्म (brahma) - Brahman; चतुर्मुखः (caturmukhaḥ) - four-faced;]
The 'brahma' referred to in the context is the four-faced.
॥इति प्रथमः खण्डः॥
॥iti prathamaḥ khaṇḍaḥ॥
[इति (iti) - thus; प्रथमः (prathamaḥ) - first; खण्डः (khaṇḍaḥ) - section;]
Thus ends the first section.