About fifty or sixty years back, the eminent religious scholar of Egypt, Muhammad Fu'wad Al- Baqi made a collection of Ahadith and named it as Al-Lu-'lu'wal- Marjan, Fima Ittafaqa alaihi Ash-Sheikhan (The Diamonds and the Pearls on which the two Sheikh are agreed upon). The Shiekhs refer to the collection of Ahadith of Imam Bukhari and Imam Muslim. The Ahadith which are common in both the collections are termed as 'Agreed upon' and possess the highest degree of authenticity.
In fact, these Ahadith are much more than the diamonds and pearls for us from the Prophet. The scholars of Hadith have compiled the books of Ahadith after a thorough search, vast investigations, careful examinations, systematic studies and close analysis regarding their authenticity.