Jami' at-Tirmidhi

At-Tirmidhi's al-Jami' as-Sahih is distinguished from the other Sunan works by stating the grade of each hadith (sahih, hasan, gharib) and summarising the positions of the legal schools on the topic at hand. It is therefore read both as a hadith collection and as a work of comparative jurisprudence; the currency of the term hasan in hadith science owes much to this book.