(1) Abu Tahir Ahmad ibn Muhammad ibn Ahmad ibn Ibrahim ibn Sulfa al-Isfahani was a prolific hadith master of the Shafi‘i school. Born in 472 AH, he died in Alexandria in 576 AH. See: Wafayat al-ayan 1:105, 107 (no. 44); al-Lubab fi tahdhib al-ansab 2:126. (2) Abd Allah ibn Sulayman ibn al-Ashath al-Sijistani, the reliable hadith scholar and author—son of Abu Dawud, compiler of the Sunan—was described by al-Daraqutni as “reliable, though he often errs when commenting on hadith,” a judgment echoed in part by his father. Al-Khalili, however, called him “the hadith master, imam of his age, and a unanimously acknowledged authority.” He was born in 235 AH and died in 316 AH. See: Lisan al-mizan 3:293–297 (no. 1238). (3) Isa ibn Hammad ibn Muslim ibn Abd Allah al-Tujibi, Abu Musa, an Egyptian nicknamed Zughbah (some say the nickname belonged to his father), was declared trustworthy by al-Nasai, Abu Hatim, and al-Daraqutni; Ibn Hibban also listed him among the reliable narrators. His traditions appear in Sahih Muslim, Sunan Abu Dawud, and other collections. He died in 248 AH at the age of ninety. See: Tahdhib al-tahdhib 8:209–210 (no. 386). (4) Ibn Hibban said of him, “It is not permissible to record his hadith except out of amazement.” Al-Daraqutni deemed him weak and on another occasion accused him of fabrication, a verdict shared by al-Hakim and the rest of the critical scholars. See: Lisan al-mizan 4:212–214 (no. 562). (5) Khalid ibn Dalaj al-Sadusi al-Basri was judged weak by Ahmad, Ibn Ma‘in, and others; he died in 166 AH. See: Tahdhib al-tahdhib 3:158–159 (no. 301).