The Köprülü Library in Istanbul, under number 294-2, and it is of the utmost rarity and quality, written in the hand of al-Ḥāfiẓ Ibn Ḥajar al-ʿAsqalānī, as I later ascertained with certainty. We have already described it in the introduction to the book, so refer to it. (1)

This book is well known and famous through the transmission of Abū ʿAlī Muḥammad ibn Aḥmad ibn ʿAmr al-Luʾluʾī.

3 - "Al-Nāsikh wa al-Mansūkh" (The Abrogating and the Abrogated): This is among the valuable books of Imam Abū Dāwūd. Ibn al-Abbār (658 AH) mentioned it in his "Muʿjam Aṣḥāb Abī ʿAlī al-Ṣadafī" (2), and the ḥuffāẓ al-Mizzī, al-Dhahabī, and Ibn Ḥajar also mentioned it (3). It is known through the transmission of Abū Bakr Aḥmad ibn Salmān al-Najjād, from Abū Dāwūd.

Ibn al-Nadīm and al-Khaṭīb al-Baghdādī (4) have mentioned that Imam Abū Bakr ibn Abī Dāwūd al-Sijistānī had a book titled "Al-Nāsikh wa al-Mansūkh," so it is not unlikely that both of them composed works in this field. The book is lost, with no extant copy as far as we know.

4 - "Al-Zuhd" (Asceticism): This book was mentioned by Ibn Khayr al-Ishbīlī in his "Fahrasa" (5). A copy of it exists in al-Qarawiyyīn in Fez, and a copy in the library

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(1) Published by Muʾassasat al-Risāla in the year 1418 AH.
(2) P. 268.
(3) Al-Mizzī in "Tahdhīb al-Kamāl" in the biography of Abū Dāwūd, al-Dhahabī in "Siyar Aʿlām al-Nubalāʾ" in the biography of Abū Bakr al-Najjād 15/505, and Ibn Ḥajar in "Al-Muʿjam al-Mufahras" (373). Ibn Ḥajar heard it and had it in his possession.
(4) Al-Nadīm in "Al-Fihrist" p. 288, and al-Khaṭīb in "Tārīkh Baghdād" 9/464.
(5) P. 109.