The '''Kereyana''' (ܩܪܐܢ) is a madnhâyâ script Garshuni compilation of spiritual lessons given by the Kahans to those who have taken clerical vows among the Kypchaqs of the Kara-Tat, Kiraim-Tat, Khvar-Tat, and Gok-Tat hordes.
It seems to have originated in Southern Syria between the years 604CE and 628CE among those preserving the lifestyle of the clerics evicted from Mount Izla and Nusaybin by Babai "the Great" of the Nestorian Church.
