ʿeltā
In the Syriac literature, an ʿeltā (plural ʿellātā) is a work explaining the reasons behind feast days, aspects of the liturgy or some other part of church tradition. It is a distinctive literary genre of the Church of the East and is strongly associated with the schools, such as the School of Nisibis and the School of Seleucia-Ctesiphon. It flourished between the 6th and 8th centuries.
The word ʿeltā is Syriac for "cause" or "explanation". The genre may be called "cause literature" in English.