Shatapatha Brahmana 6.3.1.15

6.3.1.15

yuktvāya savitā devāniti | mano vai savitā prāṇā devāḥ svaryato dhiyā divamiti svargaṃ haināṃlokaṃ yato dhiyaitasmai karmaṇe yuyuje bṛhajjyotiḥ kariṣyata ityasau vā ādityo bṛhajjyotireṣa u eṣo 'gniretamvete saṃskariṣyanto bhavanti savitā prasuvāti tāniti savitṛprasūtā etatkarma karavannityetat

[Vâg. S. XI, 3] 'Savitri, having harnessed the gods,'--Savitri is the mind, and the gods are the vital airs;--'going by thought to the light, to heaven,'--for as such as are going to the heavenly world by thought (devotion) he has harnessed them for this holy work;--'going to produce a mighty light,'--the mighty light assuredly is yonder sun, and he is this Agni, and him they are indeed going to fit together (or, restore);--'may Savitri speed them!'--that is, 'may they perform this holy work, sped by Savitri.'