Kaushitakagrihyasutra 3.2.2

3.2.2

na ca sthūṇāgartān khānayitvodamanthānāsicya imāṃ viminve 'mṛtasya śākhāṃ madhordhārāṃ prataraṇīṃ vasūnām enāṃ śiśuḥ krandatvā kumāra enāṃ dhenuḥ pāvakavathsa ityudumbaraśākhāṃ ghṛtenāktāṃ dakṣiṇe dvārye garte 'vadadhāti \2\

And not having had the post-holes dug, having poured out water mixed with flour, with “I erect this branch of immortality, a stream of sweetness, bringing forth treasures; / may the child cry towards this, may the boy [run towards it], may the purifying-calf milk-cow [approach it],” he places an udumbara branch anointed with clarified butter into the southern door-hole.