Śatapatha Brāhmaṇa ("of a hundred paths") 8.3.4.7

8.3.4.7

yadveva vālakhilyā upadadhāti | etadvai devā vālakhilyābhirevemāṃlokāntsamayuritaścordhvānamutaścārvācastathaivaitadyajamāno vālakhilyābhirevemāṃlokāntsaṃyātītaścordhvānamutaścārvācaḥ

And, again, as to why he lays down the Vâlakhilyâs,--it was by means of the Vâlakhilyâs that the gods then ranged over these worlds, both from hence upwards and from yonder downwards; and in like manner does the sacrifice now, by means of the Vâlakhilyâs, range over these worlds, both from hence upwards and from yonder downwards.