This is an opuscule of forty hadiths by Imam Ibn Hajar which he narrates from forty different Companions through forty shuyukh in a myriad of places; from the old Salihiyya quarter of Damascus to the Riyad-al-Jannah in the Prophet's Mosque. The book is a joy to read since not only the subject matter is interesting but the actual isnads of the hadith with their special features. Writing forty hadith collections has been an old scholarly tradition tracing its origins to Abdullah ibn Mubarak, its justification going as far back as to the Prophet. In this respect, the reader becomes a part of this blessed historical tradition, especially with Ibn Hajar's initiation of the book with the hadith, "al-musalsal biʾl-awwaliyya." Imam Ahmad ibn ʿAli al-ʿAsqalāni (d. 852/1448), famously known as Ibn Hajar after one of his ancestors, is arguably the best hadith scholar of the Mamluk period. The Dhahabi of his time and the Amir al-Muminin of the hadith scholars. The scholar Jalal ad-Din as-Suyuti says that Ibn Hajar drank from the well of Zamzam and prayed to Allah to give him more knowledge than Shams ad-Din adh-Dhahabi. He is the author of over 300 books some going into lengthy volumes. He died on Friday 28 Dhuʾl-Hijja 852 AH and was buried in al-Qarrafa, Cairo, now famously known as the City of the Dead (Madinat al-mawta).