A member of a family noted for scholarship and judicature, he taught at the shrine of Abū Ḥanīfah and served as deputy to the Chief Judge Ibn Faḍlān, the Shāfiʿī; then to the Chief Judge Abū Ṣāliḥ Naṣr ibn ʿAbd al-Razzāq (1), the Ḥanbalī; and thereafter to the Chief Judge (2) ʿAbd al-Raḥmān ibn Muqbil al-Wāsiṭī (3). When the latter died in 633 AH, the judge ʿAbd al-Raḥmān al-Lamghānī—just mentioned—(4) assumed independent authority over the judiciary in Baghdad and was granted the honorific Aqḍā al-quḍāt (Most Senior of the Judges), though he was never addressed as Qāḍī al-quḍāt (Chief Judge) (5). In 635 AH he lectured on Hanafī jurisprudence at the Mustanṣiriyyah, and his conduct in issuing, annulling, and confirming verdicts was widely praised. After his death the office of Chief of Judges in Baghdad passed to the Shaykh of the Niẓāmiyyah, Sirāj al-Dīn al-Nahraqullī (6)—may Allah the Exalted have mercy on them both and pardon them out of His grace and generosity. Āmīn (7).

Then came the year 650 AH (8).

Events of this year:
The Mongols reached al-Jazīrah, Sarūj, Raʾs al-ʿAyn, and the surrounding districts, where they killed, captured, plundered, and laid waste—surely to Allah we belong and to Him we return. They fell upon a party of merchants (9) traveling between Ḥarrān and Raʾs al-ʿAyn, seizing six hundred loads of sugar (10) and other finished goods from Egypt, along with six hundred thousand dinars. About ten thousand inhabitants of al-Jazīrah were killed that year, and roughly the same number of women and children were taken captive. To Allah we belong and to Him we return.

Al-Sibt (11) said: In this same year the people of Baghdad performed the pilgrimage, after having gone ten years without Hajj since the days of al-Mustanṣir.