Praise be to Allah.
One of the most important things that the educated Muslim, or the Muslim who is acquainted with the classical legacy, should understand is that stirring up doubts is easy and is something that anyone could do, to stir up doubts about anything, even about basic givens and common-sense issues on which people base their rational thinking. The matter may even go so far that some of those who got carried away with doubts and specious arguments ended up denying their own existence, and doubted everything around them, which led to them being admitted to mental health clinics, because they drifted so far from common sense and sound human nature.
This is how we deal with many so-called specious arguments which are, in reality, nothing but illusions uttered by some people who are causing us trouble at this time. This always compels us to start from the very beginning in establishing principles of sound rational thinking in various fields of knowledge and education.
What is mentioned in the question is one such example. If what the questioner meant by “original copies” is manuscripts that the author wrote in his own hand, then according what rational thinking or logic can it be said that it is essential that the original manuscripts be extant in order to accept that a particular book is correctly attributed to its author?! How many books are there in the world, since people learned how to write, that could meet this irrational condition?!
In order to understand how irrational those who stipulate that condition are, all you have to do is imagine that one of them entered a venerable library or well-known publishing house or international bookstore and said to the person in charge, I will not accept the attribution of any books you have in this huge store unless you give me the original manuscript, written by the author himself, so that I will be certain that these books are soundly attributed to their authors! Doing this would be ignoring all the customs and academic and legal requirements which guarantee to us nowadays that the book is sound and that it will not be claimed by anyone other than the author, such as requirements to register books in the National Library, to get permission to publish, making books well-known to critics and providing well-established evidence to that effect, and other similar academic ways of proving such matters.
We know for certain that some of those who specialise in producing specious arguments know deep down in their hearts how foolish and silly are the things they suggest and say, but at the same time they persist in saying it because they know that merely stating his specious with regard to anything that exists will inevitably have some influence on people’s hearts and minds. Hence whatever results he gets will suffice him, even if he only manages to confuse a few people. What matters to him is that he shuffles the cards and causes confusion with regard to sound ways of thinking.
However, Saheeh al-Bukhaari was heard by ninety thousand men from Imam al-Bukhaari himself (may Allah have mercy on him), as was stated by one of his most famous students, namely Muhammad ibn Yoosuf al-Farbari (d. 320 AH). See: Tareekh Baghdaad (2/9); Tareekh al-Islam (7/375). Al-Farbari’s narration of Saheeh al-Bukhaari was famous because he lived for a long time and was precise in copying it out. He heard it from al-Bukhaari (may Allah have mercy on him) over three years, then a number of trustworthy narrators learned it from him, and from them this book became well-known.
Al-Mustamli (d. 376 AH) – one of those who narrated it from Muhammad ibn Yoosuf al-Farbari – said: I copied the book of al-Bukhaari from its original text that was with Ibn Yoosuf, and I saw that he had not completed it yet; there were many blank pages there, including some isnaads after which he had not written any hadeeths, and some hadeeths for which he had not written any isnaads. So we tried to complete that.
End quote. Narrated by al-Baaji in at-Ta‘deel wa’t-Tajreeh (1/310)
The Saheeh was narrated from al-Farbari by a number of trustworthy narrators, among the most famous of whom were the following:
Al-Mustamli (d. 376 AH), whose name was Ibraaheem ibn Ahmad
Al-Hamawi Khateeb Sarkhas (d. 381 AH), whose name was ‘Abdullah ibn Ahmad
Abu’l-Haytham al-Kashmeehani (d. 389 AH), whose name was Muhammad ibn Makki
Abu ‘Ali ash-Shabwi, whose name was Muhammad ibn ‘Umar
Ibn as-Sakan al-Bazzaaz (d. 353 AH), whose name was Sa‘eed ibn ‘Uthmaan
Abu Zayd al-Mirwazi (d. 371 AH), whose name was Muhammad ibn Ahmad
Abu Ahmad al-Jarjaani (d. 373 AH), whose name was Muhammad ibn Muhammad
Among the trustworthy students of al-Bukhaari who heard his Saheeh directly from him and transmitted it to the people with its isnaads in written form was the imam, hafiz, faqeeh and qaadi, Abu Ishaaq Ibraaheem ibn Ma‘qil ibn al-Hajjaaj an-Nasafi (d. 295). The copy of an- Nasafi was transmitted by Imam al-Khattaabi (may Allah have mercy on him), as he said in his commentary A‘laam al-Hadeeth (1/105): We heard most of this book from the narration of Ibraaheem ibn Ma‘qil an- Nasafi. Khalaf ibn Muhammad al-Khayyaam told us: Ibraaheem ibn Ma‘qil told us, from him.
This is the most famous way that the scholars of hadith had: they would read their books to their students, or their students would read their books to them. Then those books would become well-known through the students and narrators, not through the original manuscript of the author, which was one copy that he kept for himself. There were no printing presses or publishing houses at that time; instead of printing presses there was the narration of students with strong isnaads.
What would any researcher find more authentic than the transmission of trustworthy narrators narrating from the manuscripts that were read to (and checked with) the author himself and approved by him, as they said concerning the copy of as-Saghaanni: He copied it from the manuscript that was read to the author (may Allah have mercy on him)”?
See: Fayd al-Baari by al-Kashmiri.
If you want to ask about how old the manuscripts that are extant today are, the Orientalist Manjana said in Cambridge in 1936 CE that the oldest manuscript he had come across up to that point was written in 370 AH, according to the narration of al-Mirwazi from al-Farbari. See Tareekh at-Turaath by Fu’aad Sizkeen (1/228).
One of the most famous manuscripts of the book that has come down to us in modern times is the copy of al-Haafiz Abu ‘Ali as-Sadafi (d. 514 AH), which he copied from the manuscript written by Muhammad ibn ‘Ali ibn Mahmoud, which was read to Abu Dharr (may Allah have mercy on him) and has his writing on it too. It was kept by al-‘Allaamah at-Taahir ibn ‘Ashoor, who borrowed it from the library of Tobruk in Libya.
There is also the copy of the imam and hafiz Sharaf ad-Deen ‘Ali ibn Ahmad al-Yoonayni, who is known as al-Ba‘li al-Hanbali (d. 701 AH). He checked it against the original copy that was read to al-Haafiz Abu Dharr al-Harawi, and the original copy that was read to al-Aseeli, and the original copy al-Haafiz Ibn ‘Asaakir, and the original copy that was read to Abu’l-Waqt in the presence of the grammarian and linguist Ibn Maalik, the author of al-Alfiyyah (d. 672 AH).
And so on… if we were to keep listing the copies of as-Saheeh that are extant in the manuscript libraries of the world, and how close they were to the time when as-Saheeh was written, and the large numbers of those who copied and checked them, and how trustworthy they were, and how they checked their copies against the authoritative main copies, that would take a great deal of time. It is sufficient for you to go to one of the libraries where manuscripts are kept and ask about Saheeh al-Bukhaari; you will find hundreds of copies with sound chains of transmission going back to Imam al-Bukhaari himself. Al-Fihris ash-Shaamil lists 2327 locations in various libraries in which there are manuscripts of this book.
See: al-Fihris ash-Shaamil li’t-Turaath al-‘Arabi al-Islami al-Makhtoot, al-Hadeeth an-Nabawi wa ‘Uloomuhu (1/493-565).
With regard to Saheeh Muslim, it is no less well-known and widespread than the Saheeh of Imam al-Bukhaari, as Brockelmann said: Saheeh Muslim almost matches Saheeh al-Bukhaari in the number of manuscripts and their presence in most libraries, as he stated in The History of Arabic Literature (3/180)
It has many chains of transmission which confirm that the book is soundly attributed to its author. The number of such chains of transmission is almost unlimited, to such an extent that a number of scholars wrote books just to discuss the chains of transmission of Saheeh Muslim; there are eight such books, one of the last of which was the book by al-Kattaani (d. 1327 AH) entitled Juz’ Asaaneed Saheeh Muslim.
Shaykh Mashhoor Hasan Salmaan said:
A group of people learned this book from Muslim, one of the most famous of whom was Ibraaheem ibn Muhammad ibn Sufyaan. He heard it from its author no less than three times, and he checked it against the copy of his shaykh, Muslim. Muslim’s copy was very precious and dear to him; he carried it with him to ar-Rayy and placed it before Abu Zur‘ah ar-Raazi and Ibn Waarah looked at it. A number of scholars learned it from Sufyaan; among them was al-Jaloodi. His copy was in circulation among the students and some of them made a copy of it… Many of these copies were very precise and were read to some prominent scholars and checked against other manuscripts. Therefore the scholars used it as a reference for research and discussion; they used to refer to it when dealing with issues and problems. There are many manuscript copies of as-Saheeh in libraries throughout the world, and hardly any library is without it. These copies vary in the dates at which they were copied and they vary in condition.
In the library of al-Qarawiyyeen in Fez up till now there is a very precious copy of it; this is the copy of Ibn Khayr al-Ishbeeli, which he checked many times (against other manuscripts); he heard it read to him and he read it to other shaykhs, to such an extent that it is regarded as the greatest extant manuscript of Saheeh Muslim in North Africa. Written on it in the handwriting of Ibn Khayr is a note stating that he checked it against three other original manuscripts of the copy of al-Haafiz Abu ‘Ali al-Jiyaani.
End quote from al-Imam Muslim ibn al-Hajjaaj wa Manhajuhu fi’s-Saheeh (1/375-376)
As for the claim that “some of the commentators on al-Bukhaari discussed the meaning of some hadeeths that are not in al-Bukhaari”, we have not found a single example of that. Differences in the reports in Saheeh al-Bukhaari only occur in a few, very minor cases having to do with the isnaads or some phrases in the texts, or the chapter headings. But to suggest that there are some independent hadeeths under some headings that were mentioned in some manuscripts but not others, we could not find any example of that.
Even if we assume that they exist, it is not something to object to or find strange. If the narrators who narrated from the Prophet (blessings and peace of Allah be upon him) differed sometimes, whereby some of the Sahaabah narrated the hadeeth with a particular wording, and others narrated it with a different wording, or some of the Sahaabah narrated a hadeeth and others did not remember it, in dozens of examples, that does not undermine the principle of the Prophetic Sunnah, and it does not shed doubt on the trustworthiness of the Sahaabah who narrated from the Prophet (blessings and peace of Allah be upon him). So it is more appropriate that the fact that there are slight differences between the narrators of al-Jaami‘ as-Saheeh should not undermine the basic authenticity of the book or its trustworthiness or its hadeeths and reports.
We do not doubt that a lack of experience in dealing with the classical Islamic legacy – and indeed a lack of knowledge about the nature of history and manuscripts altogether – is the reason for such misleading ideas or extreme ignorance and lack of understanding on the part of the one who says that.
Otherwise, anyone who has any knowledge of these branches of knowledge will be certain that minor differences in reports or manuscripts in classical books is something natural in the light of the fact that people in the past relied on copying by hand, and because means of communication were very simple, and copyists were sometimes imprecise in adhering to the original text; indeed they were sometimes unaware of alterations that the author himself had introduced to his book that would lead to some differences in the copies, as happened in the case of Sunan at-Tirmidhi, Sunan Abi Dawood, al-Muwatta’ by Imam Maalik, and the Musnad of Imam Ahmad ibn Hanbal. Indeed that also happened in the case of the poetry of the Jaahiliyyah before that, and in the books of Plato, Aristotle, and the entire legacy of Greek philosophy, and in the case of both the Torah and the Gospel.
We hope that by giving these brief highlights, readers will be alerted to the nature of these specious arguments that are made and will realise that a little rational thinking, with a little experience, will be sufficient to ward off all these specious arguments.
See: Riwaayaat wa Nusakh al-Jaami‘ as-Saheeh li’l-Imam Abu ‘Abdullah Muhammad ibn Ismaa‘eel al-Bukhaari: Diraasah wa Tahleel, by Dr. Muhammad ibn ‘Abd al-Kareem ibn ‘Ubayd, which was of great use to us in preparing the answer given above.
And Allah knows best.