A kind of Utkālika Śruta (a category of Āgamas (canonical works), which is allowed to be studied at all time barring the akāla prahara (i.e., the period in which the study of Āgamas is prohibited)),
which depicts the various means of spiritual purification.
āta tti ātmā, tassa visohī taveṇa caraṇaguṇehiṃ ya āloyaṇāvihāṇeṇa ya jahā bhavati tahā jattha ajjhayaṇe vaṇṇijjati tamajjhayaṇaṃ ātavisohī.
(Nandī 77 Cū p.58)