Śatapatha Brāhmaṇa ("of a hundred paths") 13.5.4.6

13.5.4.6

ete eva pūrve ahanī mahāvratamatirātrastena ha marutta āvikṣita īja āyogavo rājā tasya ha tato marutaḥ pariveṣṭāro'gniḥ kṣattā viśve devāḥ sabhāsado babhūvustadetadgāthayābhigītam marutaḥ pariveṣṭāro maruttasyāvasangṛhe āvikṣitasyāgniḥ kṣattā viśve devāḥ sabhāsada iti maruto ha vai tasya pariveṣṭāro'gniḥ kṣattā viśve devāḥ sabhāsado bhavanti yo'śvamedhena yajate

Those same first two days, and a Mahâvrata Atirâtra,--therewith Marutta Âvikshita, the Âyogava king, once performed sacrifice; whence the Maruts became his guards-men, Agni his chamberlain, and the Visve Devâh his counsellors: it is of this that the Gâthâ sings,--'The Maruts dwelt as guards-men in Marutta Âvikshita's house, Agni as his chamberlain, and the Visve Devâh as his counsellors.' And, verily, the Maruts become the guards-men, Agni the chamberlain, and the Visve Devâh the counsellors of him who performs the horse-sacrifice.