Expositio officiorum ecclesiae
Nuhrā d-Tešmeštā ʿEdtānāytā ("Commentary of the Ecclesiastical Services"), better known by its Latin title, Expositio officiorum ecclesiae, is an anonymous Syriac commentary on the East Syriac liturgy. Its author is usually referred to as Pseudo-George of Arbela (or Pseudo-Gewargis). The work is dedicated to a certain Daniel. The "Expositio" is preserved in many manuscripts. It is the longest preserved Syriac liturgical commentary. Its date is uncertain. It was probably written in the ninth century, but perhaps as early as the seventh. It quotes the seventh-century author Abraham bar Lipeh, whose work is based  on that of Gabriel Qaṭraya, and must have been written after the liturgical reforms of the Catholicos Ishoʿyahb III (). In the 18th century, Giuseppe Simone Assemani assigned the "Expositio" to George of Arbela, but he gave no reasons. As George lived in the tenth century, this attribution has been discredited. The "Expositio" has also been wrongly credited to ʿAbdishoʿ bar Bahrīz. The "Expositio" is structured as a series of question on liturgical practices, divided between seven sections: The "Expositio" has been translated into Latin, but not any modern language.