Imaam Muslim (rahimahullah) once mentioned, “I did not include every Saheeh Hadith in my kitaab (as the total number of Saheeh Ahaadith is much more than the number of Ahaadith found in Saheeh Muslim). However, all the Ahaadith I placed in my kitaab have been unanimously regarded as authentic by a specific group of Muhadditheen (who were from his ustaads).”

Allamah Bulqeeni (rahimahullah) has mentioned that this group comprised of four of the leading Muhadditheen of their era. These four great Muhadditheen were; (1) Imaam Ahmed bin Hambal (rahimahullah), (2) Imaam Yahya bin Ma’een (rahimahullah), (3) Imaam Uthmaan bin Abi Shaybah (rahimahullah) and (4) Imaam Sa’eed bin Mansoor Khurasaani (rahimahullah). (Ma-Tamassu ilayhil Haajah pg. 21)