About “Al-Mustadrak ala al-Sahihayn”
Al-Mustadrak 'ala al-Sahihayn, also known as Mustadrak Al Hakim, is a five-volume hadith collection compiled by Hakim al-Nishapuri. The work was written in the year AH 393, when the author was 72 years old. It is a compilation of hadiths that the author considered to be authentic but were not included in the two major collections, al-Sahih al-Bukhari and Muslim. The purpose of the work was to gather additional hadiths that met the criteria of authenticity but had been overlooked in previous collections. (Summary adapted from Wikipedia, CC BY-SA 4.0.)
Some summaries adapted from Wikipedia, CC BY-SA 4.0.