Atharvaveda 11.3.44

11.3.44

[4.13]a) tátaś cainam anyā́bhyām ūrúbhyāṃ prā́śīr yā́bhyāṃ caitáṃ pū́rva ŕ̥ṣayaḥ prā́śnan |
[4.13]b) ūrū́ te mariṣyata íty enam āha |
[4.13]c) táṃ vā́ aháṃ nā́rvā́ñcaṃ ná párāñcaṃ ná pratyáñcam |
[4.13]d) mitrā́varuṇayor ūrúbhyām |
[4.13]e) tā́bhyām enaṃ prā́śiṣaṃ tā́bhyām enam ajīgamam |
[4.13]f) eṣá vā́ odanáḥ sárvāṅgaḥ sárvaparuḥ sárvatanūḥ |
[4.13]g) sárvāṅga evá sárvaparuḥ sárvatanūḥ sáṃ bhavati yá eváṃ véda ||44|| [13]

If thou hast eaten it with other thighs than those with which the ancient seers ate this, thy thighs will die: thus one says to him; it verily [have] I not [eaten] coming hither, nor retiring, nor coming on; with the thighs of Mitra-and-Varuṇa, therewith have I etc. etc.