Bhagavatapurana 3.6.30

3.6.30

mukhato 'vartata brahma puruṣasya kurūdvaha /
yas tūnmukhatvād varṇānāṃ mukhyo 'bhūd brāhmaṇo guruḥ //

30. O best of Kurus, out of the face (mouth) of the Virat Purusha issued Brahman (the Veda); as well as the Brahmin who (like letters), as issuing from the mouth, became

the foremost among all the Varnas (worthy of being esteemed and worshipped by all the Varnas).