Gobhilagrihyasutra 2.6.10

2.6.10

prātaḥ saśiraskā ''pluto 'dagagreṣu darbheṣu, paścād agner udagagreṣu darbheṣu prākśirāḥ saṃviśati;

In the morning, after she has been washed, sitting on northward-pointed Darbha grass, (all over her body), including her head, she lies down to the west of the fire on northward-pointed Darbha grass, with her head to the east.