The Religion and Philosophy of the Veda and Upanishads v2.c30.s18.3

v2.c30.s18.3

The model of all Sattras is the Dvādaçāha, which is made up of a Prāyaṇīya and an Udayanīya, which, as in all Sattras as opposed to Ahīnas, must both be Atirātra days, as the beginning and concluding rites respectively of a Pṛṣṭhya Ṣaḍaha, and of either 4 Chandomas or 3 Chandomas and an Avivākya day as the tenth. The name Pṛṣṭhya is based on the different treatment of the Pṛṣṭha Stotra of each day corresponding to the Çastra of the Hotṛ: on the first it is in the Rathantara tune, on the second the Bṛhat, the third the Vairūpa, the fourth the Vairāja, the fifth the Çākvara, the sixth the Raivata. Of these days the first and fourth are Agniṣṭomas, the others Ukthyas. The Chandomas are Ukthyas, the tenth is an Atyagniṣṭoma: it is called Avivākya, because on that day no dispute about errors in the ceremony is allowed.¹ A further variation is possible: on the fourth and ninth days the Āgrayaṇa cup may be drawn first, on the six and seventh the Çukra, in which case the Stotras and the Çastras must also be transposed, or they may be transposed without change in the order of the cups: this makes the period of ten days bear the term *vyūḍhachandas*. The Soma is daily watched by one priest, the rest may study the Veda, fetch wood, and eat. The tenth day is marked by interesting rites, the singing of the Sāman called the success of the Sattra, and the performance of a Brahmodya like that at the horse offering or regarding the unqualified Prajāpati.