(1) In other manuscripts: “al-Hasan ibn Ahmad,” which is his personal name. (2) In other manuscripts: simply “Abu Sahl.” (3) In manuscripts H and M: “al-Birti” only; in R: “Ahmad ibn Muhammad al-Birti,” omitting ‘Isa. He is commonly known by the nisba al-Birti—spelled with a kasra under the b and a sukun on the r—denoting origin from Birt, a village near Baghdad. Another scholar bearing this nisba is al-Abbad ibn Ahmad. See al-Libab, vol. 2, p. 133. (4) That is, an addition beyond the angels assigned to the creation; it is also transmitted as ziyādah, some stating that the reading with sukun on the d is more frequent and more correct. Both forms are masdar (verbal nouns) meaning “excess” or “abundance.” See al-Nihayah fi Gharib al-Hadith, vol. 3, p. 455.