Gobhilagrihyasutra 2.7.3

2.7.3

prātaḥ saśiraskā ''pluto 'dagagreṣu darbheṣu, paścād agner udagagreṣu darbheṣu prācy upaviśati;

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