Jaiminīya (Talavakāra) Brāhmaṇa 58.335

58.335

tasya yatprathamamulbamapālumpaṃstatkṛṣṇāyassamabhavat
yaddvitīyamulbamapālumpaṃstadrajatamabhavat
yattṛtīyamulbamapālumpaṃstaddharitamabhavat
tasmāttattviṣimattamam
tattaddhyasyādhyātmamāsīdatha yajjarāyu nāḍyāmāsīt
tallohamabhavat
tasmāttaddurgandhitamam
tāni saptadaśaivākṣarāṇyajāyanta
tāni dvedhā vyauhannavānyānyaṣṭāvanyāni
sa eva trivṛcca stomo'bhavadgāyatrī ca chandaḥ
sa ṣakṣatāyaṃ stoma idaṃ chanda imau vāva tasmā alaṃ yatprajanayetām
hantaimāveva prajanayatamiti bravāṇīti
sa trivṛtā stutvābravīdgāyatrīṃ vibhava | yāvatyasi tāvatyedhīti
sāṣṭākṣarā satyakṣarāṇi tryakṣarāṇyakuruta
tāni caturviṃśatirabhavan
so'syai gāyatryai caturviṃśatyakṣarāyai ṣaḍakṣarāṇyādatta

The first caul that they stripped off him became black iron (iron).
The second caul that they stripped off became silver.
The third caul that they stripped off became gold.
Therefore it is the most radiant.
For that was closest to his self; and the afterbirth that was in the vein
became copper.
Therefore it is the most foul-smelling.
Just seventeen syllables were born.
They divided them in two: nine were one, eight were the other.
That became the trivṛt stoma and the gāyatrī meter.
He saw: "This is the stoma, this is the meter; these two indeed are capable of bringing forth for him.
Come, let me say to these two: 'Bring forth!'"
Having praised with the trivṛt, he said to the gāyatrī: "Become pervasive! Grow as great as you are!"
Being of eight syllables, she made each syllable into three syllables.
They became twenty-four.
From this twenty-four-syllabled gāyatrī he took six syllables.