Jaiminīya (Talavakāra) Brāhmaṇa 3.6

3.6

tasmādasāvarvāṅādityastapati
tejasā vai gāyatrī prathamaṃ triyahaṃ dādhāra | padairdvitīyam | akṣaraistṛtīyam
trivṛdvai gāyatrī tejaḥ
trivṛtprathamamahaḥ
tena prathamastriyaho dhṛtaḥ
tripadā gāyatrī | triyaho madhye | tena dvītīyastriyaho dhṛtaḥ
caturviṃśatyakṣarā gāyatrī | caturviṃśaṃ saptamamahas | tenaiva tṛtīyastriyaho
dhṛtaḥ
kathaṃ gāyatrī dvādaśāhamityāhuḥ
yathārānnemissarvataḥ paryety | evaṃ gāyatrī dvādaśāhaṃ sarataḥ paryetyavisraṃsāya
yathā rathanābhāvarā dhṛtā evaṃ gāyatryāṃ dvādaśāho dhṛto'saṃplavāya
mayūkho vā eṣa vā dharuṇo yadgāyatrī
tasyāṃ dvādaśāho dhṛto'saṃvyāthāya
anuṣṭubvā eṣā pratāyate yaddvādaśāhaḥ
aṣṭābhirvā akṣarairanuṣṭupprathamamaharudyacchaty | ekādaśabhirdvitīyaṃ
dvādaśabhistṛtīyam
akṣarameva triyakṣaraṃ pariśiṣyate
tadevottaraṃ triyahamanuvidadhāti

Therefore yonder sun burns downward. By means of fiery splendor the Gāyatrī held fast the first three-day period, by means of feet the second, by means of syllables the third. The Gāyatrī is threefold fiery splendor; the first day is threefold. By that the first three-day period is held fast. The Gāyatrī has three feet; the three-day period is in the middle. By that the second three-day period is held fast. The Gāyatrī has twenty-four syllables; the seventh day is twenty-four-fold. Just by that the third three-day period is held fast. They say: 'How does the Gāyatrī hold the twelve-day rite?' Just as the felly goes around the spokes on all sides, so the Gāyatrī goes around the twelve-day rite on all sides for the sake of firmness. Just as the spokes are held fast in the nave of the chariot, so the twelve-day rite is held fast in the Gāyatrī against confusion. A peg or a support is this Gāyatrī; on it the twelve-day rite is held fast against wobbling. Indeed, this Anuṣṭubh is stretched out as the twelve-day rite. With eight syllables the Anuṣṭubh raises the first day, with eleven the second, with twelve the third. Just one tri-syllable is left over. That very one he disposes along the next three-day period.