Atharvaveda 11.3.46

11.3.46

[4.15]a) tátaś cainam anyā́bhyāṃ pā́dābhyāṃ prā́śīr yā́bhyāṃ caitáṃ pū́rva ŕ̥ṣayaḥ prā́śnan |
[4.15]b) bahucārī́ bhaviṣyasī́ty enam āha |
[4.15]c) táṃ vā́ aháṃ nā́rvā́ñcaṃ ná párāñcaṃ ná pratyáñcam |
[4.15]d) aśvínoḥ pā́dābhyām |
[4.15]e) tā́bhyām enaṃ prā́śiṣaṃ tā́bhyām enam ajīgamam |
[4.15]f) eṣá vā́ odanáḥ sárvāṅgaḥ sárvaparuḥ sárvatanūḥ |
[4.15]g) sárvāṅga evá sárvaparuḥ sárvatanūḥ sáṃ bhavati yá eváṃ véda ||46|| [15]

If thou hast eaten it with other feet than those with which the ancient seers ate this, thou wilt be much-wandering: thus one says to him; it verily [have] I not [eaten] coming hither, nor retiring, nor coming on; with the feet of the two Açvins, therewith have I etc. etc.