Gobhilagrihyasutra 2.6.11

2.6.11

paścāt patir avasthāya, dakṣiṇasya pāṇer aṅguṣṭheno 'pakaniṣṭhikayā cā 'ṅgulyā 'bhisaṃgṛhya dakṣiṇe nāsikāsrotasy avanayet pumān agniḥ pumān indra ity etaya rcā.

Her husband, standing behind her, should seize (the pounded Nyagrodha shoot) with the thumb and the fourth finger of his right hand, and should insert it into her right nostril with the verse, 'A man is Agni, a man is Indra' (MB. I, 4, 9).