Apastambagrihyasutra 6.15.6

6.15.6

uttareṇa yajuṣā śirasya udakumbhaṃ nidhāya sarṣapānphalīkaraṇamiśrānañjalinottaraistristripratisvāhākāraṃ hutvā saṃśāsti praviṣṭe praviṣṭa eva tūṣṇīmagnāvāvapateti \ 6 \

With the next Yagus (II, 13, 6) he places a water-pot at (the child's) head, sacrifices mustard seeds and rice-chaff with his joined hands three times with each of the next (formulas, II, 13, 7-14, 2), repeating each time the word Svâhâ, and says (to the people who are accustomed to enter the room in which his wife lies), 'Whenever you enter, strew silently (mustard seeds with rice-chaff) on the fire.'