The eldest brother, known as Majd ad-Dīn (1149–1210), was long in the service of the amir of Mosul, and was an earnest student of tradition and language. His dictionary of traditions (Kitāb an-Ni/zdya) was published at Cairo (1893), and his dictionary of family names (Kitāb ul-Murassa) has been edited by Ferdinand Seybold (Weimar, 1896).