Hiranyakeshigrihyasutra 2.8.19.3

2.8.19.3

nivītina uttarata udīcīnapravaṇa udagagrairdarbhaiḥ prāgapavargāṇyāsanāni kalpayanti viśvāmitrāya jamadagnaye bharadvājāya gautamāyātraye vasiṣṭhāya kaśyapāya \3\

Wearing their sacrificial cords below (round their body) they arrange towards the north, at a place that is inclined towards the north, seats of northward-pointed Darbha grass, so that they end in the east, for Visvâmitra, Gamadagni, Bharadvâga, Gautama, Atri, Vasishtha, Kasyapa.