He was born Asmar Ṣlewa Scher in 1867 in Shaqlāwa near Arbela. Both his father, Yaʿqub, and his grandfather, Yoḥannan b. Ibrāhīm, were priests. He studied under his father and in 1879 entered the Seminary of St. John in Mosul. He was ordained a priest in 1889 and became the secretary of Bp. Gabriel Adamo (1873–99) of Kirkuk after whose death Scher administered the diocese for one year. In 1900 he became the secretary of the next bp., Eliya Khayyāṭ. In 1902 he was consecrated bp. of Siirt. In 1908 he traveled to Beirut, Constantinople, Rome, and Paris seeking funds to aid his poor diocese where he met a number of Syriac scholars. During World War I, the Ottoman Turks conspired to kill him, but he initially escaped with the aid of Kurds under Badr Khan. His escape resulted in a massacre where many Christians were killed. Finally, the Turkish army found him, tortured, and beheaded him on 15 June 1915. It is said that prior to his escape, he hid the manuscripts that he had in a well.

Scher published a number of important texts, with FT, in European series and periodicals, notably the Chronicle of Siirt (PO 4:3, 1907; 5:2, 1910; 7:2, 1910; 13:4, 1918), Barḥadbshabba’s ‘Cause of the Foundation of the Schools’ (PO 4:4, 1907), works by Ishai and Ḥenana (PO 7:1, 1910), and Theodoros bar Koni’s ‘Book of the Scholion’ (CSCO 55, 69, 1910, 1912). He also published a number of catalogues of collections of manuscripts in the Middle East (list in Macuch 403–4). His two most important works in Arabic are Kitāb ašhar šuhadāʾ al-mašrīq (2 vols.; Mosul, 1900, 1906) and Taʾrīkh Kaldū wa-Āthūr (2 vols.; Beirut 1912–3).

See Fig. 108.