Q:- The importance of the six books in hadith has been exagerated in western scholarship, as well as among modernist Muslims. Sahih Bukhari, for example, served mainly as a ritual tool in the late Middle Ages. Al-Ghazali, whose works are very important for the Shafi'i madhhab only started to learn the two Sahihs shortly before his death.
The two Sahihs were already canonic generations before al-Daraqutni (306-385) as shown by the earlier critiques, commentaries, and Mustakhrajs of: Ibn Abi Hatim (d. 327) on al-Bukhari; Ibn al-Akhram (250-344) on al-Bukhari and Muslim; Ibn `Abduyah (260-345) and Ibn `Adi (277-365) on al-Bukhari; al-Masarjasi (297-365) and Ibn Abi Dhuhl (294-378) on al-Bukhari and Muslim; al-Ghitrifi (d. 377) and Abu Ahmad al-Hakim (285-378) on al-Bukhari....
As for Imam al-Ghazali (450-505) he was no different than the other great Mujtahids in that he was thoroughly familiar with the two Sahihs. Ibn `Asakir in his Tabyin and al-Dhahabi in the Siyar mention that al-Ghazali took al-Bukhari’s Sahih from Abu Sahl Muhammad ibn Ahmad al-Hafsi, meaning he read it with him from cover to cover. Since the latter died in 465 or 466, it means al-Ghazzali was at the most 15 or 16.
Ibn al-Jawzi narrated in al-Thabat ‘ind al-Mamat (“Firmness at the Time of Death”) from al-Ghazzali’s brother the “peerless admonisher” Ahmad:
“On Monday [14 Jumada al-Akhira] at the time of the dawn prayer my brother Abu Hamid made his ablution, prayed, then said: ‘Bring me my shroud.’ He took it, kissed it and put it on his eyes, saying: ‘We hear and obey in readiness to enter the King’s presence’ (sam`an wa-ta`atan lil-dukhuli `alal-Malik). Then he stretched his legs, facing the Qibla, and died before sunrise – may Allah sanctify his soul!” As cited by Sibt Ibn al-Jawz? in Mir’at al-Zaman (8:40) and Ibn al-Subki in Tabaqat al-Shafi`iyya al-Kubra (6:201).
Even if it were accurately reported that at the time al-Ghazali died he was reading Sahih al-Bukhari, this does not mean it was the first time he opened that book. If he died with an open Mus-haf in front of him it would not mean he was just beginning to memorize the Qur’an.
At the end of Qanun al-Ta’wil Imam Ghazali humbly stated of himself: “Know that my wares in the science of hadith are poor.” This disclaimer only typifies the Friends of Allah that abhor self-promotion even in what they know. In reality al-Ghazali is a bottomless ocean of hadith. In the book of `ilm of the Ihya’, in the section listing the minimum syllabus of the Muslim student he states:
“As for Hadith, the bare minimum in it is to become thoroughly familiar with the two Sahihs, verifying your copy by reading it with an expert in the science of hadith-texts.... and it is not necessary for you to memorize the texts of the two Sahihs but only familiarize yourself with them thoroughly. This way, you can obtain whatever you need out of them at will. If you want more then add to them other compilations such as the narrations in the sound Musnads. As for the maximum then it encompasses everything else besides whether weak, strong, or sound together with knowledge of the many chains of transmission that are conveyed and mastery of the status of the narrators, their names, and their attributes.”
In Ihya `Ulum al-Din there are close to 1,000 references to hadiths in the two Sahihs not to mention other compilations. Allah have mercy on him.