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.
[1] 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 (r. 642–659).
[2][4] In the 18th century, Giuseppe Simone Assemani assigned the Expositio to George of Arbela, but he gave no reasons.
[1] As George lived in the tenth century, this attribution has been discredited.
[4][5] The Expositio has also been wrongly credited to ʿAbdishoʿ bar Bahrīz.