and he may be referring to the Messenger’s hadith...
and he may be referring to the Messenger’s hadith: “I am leaving behind among you that which if you hold fast to, you will never go astray: the Book of Allah.” He confined his will and recommendation to the Book of Allah since it is greater and more important than anything else, and containing manifestation of everything, either through the text or by means of inference (istinbat). So if people follow what the Qur’an contains, they will verily act according to whatever it commanded them to do.
The hadith to which Ibn Hajar referred, was reported by Muslim in the course of citing the Hijjat al-Wada’ (Farewell Pilgrimage) made by the Prophet (S), who said: “O people, I am leaving among you that which if you hold on to, you shall never go astray.” In another narration reported by Jabir as saying: The Messenger of Allah addressed us on the Day of Arafat saying: “I am leaving among you that which you will never go astray, if you hold fast to it: the Book of Allah.” And in al-Muwatta’: “and my sunnah”, while the Sunnah known at that time was only the practical Sunnah (the Prophet’s acts).
In another version of the narration, he said: “Verily, I am leaving behind two precious things (thaqalayn) among you: the Book of Allah and my kindred (‘itrah), my household ().” This hadith was reported in several different versions with the same meaning in many Sunni books, and whoever desiring to be acquainted with these narrations, can refer to the book al-Muraja’at, in which al-Sayyid Sharaf al-Din al-Musawi stated the debates that took place between him and the eminent scholar al-Shaykh Salim al-Bishri, the former chief of al-Azhar, in the page 20 and onwards, in the 4th edition.