Śatapatha Brāhmaṇa ("of a hundred paths") 11.5.2.5

11.5.2.5

ayamevottara ūrurmahāhaviḥ tasya yāni pañca havīṃṣi samāyīni tā imāḥ pañcāṅgulayaḥ kulphāvevaindrāgnaṃ havistadvai dvidevatyam bhavati tasmādimau dvau kulphāvidam māhendramidaṃ vaiśvakarmaṇaṃ tadvā aniruktam bhavati tasmāttadaniruktamatha yadidamantarudare tatpitṛyajñastadvā aniruktam bhavati tasmāttadaniruktam

The Great Oblation, indeed, is this left leg,--the five oblations which it has in common (with the other Seasonal offerings) are these five toes; and the oblation to Indra and Agni is the knuckles: this (oblation) belongs to two deities whence there are these two knuckles. The (oblation) to Mahendra is this (shank); that to Visvakarman this (thigh): this (oblation) is indistinct, whence this (thigh) also is indistinct.