In the Vedic procedure of Somayāga (Somayaga) three priests or ṛttvika (rittwika) help the high priest hotā (hota) during the collective chanting of hymns from scriptures. One of these three assisting priests is acchaāvāka (achchhavaka); the other two are called maitrāvaruṇa (maitravaruna) and brāhmaṇācchaṃsī (brahmanachchhamsi). Together, these three assistants are called hotraka. A shed or maṇḍapa (mandapa) called sadaḥśālā (sadahsala) is erected to the west of the vedī (vedi; altar) created for the purpose of Somayāga. A row of six round-shaped or rectangular hearths, called dhiṣñya (dhishnya), are made in that maṇḍapa.  Six priests chant Vedic hymns during Somayāga, sitting at these dhiṣñya in the following order: acchāvāka, neṣṭā  (neshta), potā (pota), brāhmaṇācchaṃsī, hotā and maitrāvaruṇa. According to Vāyupurāṇa (Vayupurana), the fire of the first hearth created on the floor of sadaḥśālāī  sitting in front of which acchāvāka performs his ritualistic duties — is considered to be the fire (agni) belonging to the celestial level of Bhuvaḥ (bhuvah). The celestial plane is divided in a number of segments, i.e., Bhū (Bhu), Bhuvaḥ, Svaḥ (Swah). Acchāvāka is associated with the fire of the plane of Bhuvaḥ.