A Collection of Knowledge and Wisdom is the translation by Muhammad Fadel of the masterwork of Ibn Rajab al-Hanbalee, Jaami' Al-'Uloom Wal-Hikam, which is his commentary on fifty ahaadeeth including Imaam An-Nawawee's Forty Ahaadeeth. Every hadith is one of those considered by Muslim scholars essential for knowledge of Islam. The topics range from the most exacting treatments of the affairs of the Sharee'ah to luminous expositions of the spiritual sciences of Islam. A very interesting book.