Imaam-ul-Haramain Al-Juwaini (rahimahullah) once mentioned, “If a person takes an oath that his wife will be divorced if the Ahaadith of Rasulullah (sallallahu ‘alaihi wasallam) found in Saheeh Bukhaari and Saheeh Muslim are not authentic, then I will neither pass the ruling that his wife is divorced nor will I say that his oath has broken. The reason is that the Ulama of the ummah have concurred on the authenticity of these two kitaabs.” (Sharh-un-Nawawi 1/19)

It is reported that a certain pious Aalim saw Abu Ali Al-Zaaghwaani (rahimahullah) in a dream after his demise and asked him, “What was the means of your salvation?” Abu Ali (rahimahullah) replied, “I received salvation on account of this kitaab that I am holding in my hand.” In the dream, Abu Ali (rahimahullah) was holding one part from the Saheeh of Imaam Muslim (rahimahullah). (Muqaddimah Fat-hul Mulhim pg. 211)