Sunan al-Saghir - Imam al-Bayhaqi (4 vol.)

It is a Sunan Book in history of Hadith collection. A book with such importance that nothing of its like has been penned down. It is compiled in a fiqh order. The author takes quite an effort in providing narrations in each chapter thereby giving the rulings of such transmissions and how certain scholars have understood it. He also expounds the problematic phrases and or terminologies that might cause misinterpretation as well as those that might seemingly portray contradictions. Many scholars have said that no such work has been penned down like the Sunan al-Saghir