Gobhilagrihyasutra 1.6.21

1.6.21

yady u vā ubhayaṃ cikīrṣed dhautraṃ cai 'va brahmatvaṃ cai 'vai 'tenai 'va kalpena chattraṃ vo 'ttarāsaṅgaṃ vo 'dakamaṇḍaluṃ darbhavaṭuṃ vā brahmāsane nidhāya, tenai 'va pratyāvrajyā 'thā 'nyac ceṣṭet.

If one wishes, however, to do himself the work both of the Hotri and of the Brahman, he should in the same way place on the Brahman's seat a parasol, or an outer garment, or a water-pot, or a bolster of Darbha grass, and should return in the same way (in which he has gone to the Brahman's seat), and then should perform the other (duties).