Bukhari states, "There was once a time during one of our sessions when my teacher Ishaaq Ibn Rahway remarked it would be appreciated if someone could collect ahadith which held strong and reliable testimonials and write them in the form of a book." This inspired Bukhari which was later strengthened by a dream in which Bukhari met the Prophet (SAW). Upon waking, he visited several interpreters for an appropriate interpretation. They all answered that it meant he would in future cleanse the Prophet (SAW) of all lies spoken by the people through narrating misunderstood ahadith. This gave Bukhari great comfort and strength once he started the writing of his book Al-Jame-ul-Sahih. The complete name of the book is ˜Al-Jame-ul-Sahih-al-Musnad-min-ahaadeethe-Rasulillah Sallallahu Alaihi Wasallam-wa-sunanihi-wa-Ayyaamihi, which means a collected version of ahadith in the form of a book which relates to us the sayings, actions and the life of the Prophet Sallallahu Alaihi Wasallam (SAW).
Bukhari had taken great care in writing the ahadith and choosing those which met the standards and conditions which he set to find ahadith with only strong testimonials which included only reliable and trustworthy testifiers. He spent 16 years in writing the book, altering it a total of three times. Allaamah Ayni reports of Ibn Tahir's remark that Bukhari had written Sahih Bukhari in his hometown Bukhara. Ibn Bujair however, relates that he had started his compiling in Makkah, and some have reported of seeing him in Basra. There is still another differing remark made by others who comment on seeing him in Madinah to write his book. However, we find Bukhari relating himself that he wrote Sahih Bukhari in Masjid-e-Haraam.
Before he actually placed a hadith in his compilation he used to perform ghusl and prayed to Allah(SWT) through two rakah nafl prayers asking for guidance. Bukhari worked such that only after being completely satisfied with the hadith in question did he give it a place in his book. Due to this great care which was taken, the people were heard to say that the ahadith which Bukhari has narrated have been so carefully phrased and with such precision that it is felt that Bukhari had heard the ahadith directly through the Prophet(SAW).
Abu Zaid Marwazi reports that I was once asleep in between the ˜Black stone' and ˜Maqaam-e-Ibrahim' when the Prophet (SAW) appeared in my dream he stated, "O Abu Zaid! For how long shall you teach Imam Shafi's book ? When shall you start the teaching of my book?"
I questioned, "O Prophet (SAW)! Which book is yours?" He replied, "Mohammed Ibn Ismail's Al-Jame-ul-Sahih."
Hafiz Ibn Hajar reports that Bukhari has kept it of utmost importance to only narrate ahadith of a strong testimonial which can be proven by the name of the book. However, along with this Bukhari also made an effort to explain all points which are difficult to understand, which is the reason why he has given a plentiful host of meanings for one sentence which may include a word that is in reality difficult to understand. Bukhari has included within his book(s) the art of narrating ahadith which have been divided into eight different chapters. These chapters contain subjects which have been sub-titled and are famous for the ingenious way in which they have been phrased.
Bukhari has imposed conditions which all narrators and testifiers must meet before the hadith can be selected. One condition requires that all testifiers must have a strong memory. There are also restrictions made upon this condition:
All the Muhadditheen who possess great knowledge of ahadith must agree upon the testifiers... in question ability to learn and memorize, along with his reporting techniques.
The testimonial must be complete without any missing testifiers.
If there are two different narrators of a hadith related to them by a Sahaabi then the hadith shall be given a high stage in rank. However, if only one narrator can be found and the testimonial proves to be a strong one then this shall be accepted without any doubts.
Allaamah Nawawi relates that all scholars in Islam have agreed that Sahih Bukhari has earnestly gained the reward of being the most authentic after the Holy Qura'an.