Ubaidullah bin Abu Qatadah narrates from his father: I heard the Prophet Muhammad (peace be upon him) say: "Among the things a man leaves behind after him, three things are the best: a righteous child who prays for him, a continuous charity whose reward reaches him, and knowledge through which benefit is obtained even after that person (has died)." Imam Ibn Hibban (may Allah have mercy on him) says: "There remain one hundred hadiths of this type, which we have mentioned in various types (i.e., chapters) of this book, because they are more appropriate to the subject matter of those chapters."