[By Shaykhul Hadith ‘Allamah Shabir Ahmad Uthmani (rahmatullah alayh)]
WHILE the revered muhaddithin have tried to record and preserve the sayings, the acts and the message of the Holy Prophet (sallallaahu alayhi wasallam) as well as his demeanour at the same time they have placed before themselves high standards for the determination of their veracity, and ensuring scrutiny, examination and investigation with due care.
This process of sifting, examination and bringing the Ahadith in conformity with the Qur’an and finding if anything remiss was suspected in the source or the putative Hadith itself (ta’dil), had commenced during the time of the Companions themselves.
And, by the grace of God, this was the measure which ensured that the Companions and the preceding generations (al-Salaf) had bequeathed the treasure of the Qur’an and Ahadith to the coming generations (al-Khalaf). The truthfulness, personality and the veracity of the authority leading to the transmissional chain that ends with the Holy Prophet (sallallaahu alayhi wasallam) were the measures for testing the genuineness of a Hadith. This was the norm adopted by the Companions. When the Science of the tradition was put on a proper plane during the pious Caliphate, the evaluatory measures also began to be practised on a sound footing. As the time-gap between the age of the Prophet (sallallaahu alayhi wasallam) and posterity began to grow wider, the evaluation became more strict and exacting.
The approach adopted by the latter-day muhaddithin was based on that laid down by the first two Pious Caliphs. While the muhaddithin of the first three generations after the time of the Holy Prophet (sallallaahu alayhi wasallam) regarded every saying attributed to him with utmost respect, they were unsparing in their examination of the narrations (ruwat-i-hadith). Bukhari was the leader par excellence of this approach. Many felt displeased with him, because he did not accept the authorities without being questioned. But, on the other hand, by the same token, a Hadith that has passed through Bukhari’s hands, enjoys the stamp of genuineness in the eyes of the muhaddithin.
It is an extreme delicate operation to decide upon the reliability of the source of a Hadith or to call that source a dubious one. A group of mystics has adhered to the view that critical assessment is prohibited according to, “Let not some of you slander others and this amounts to calumny.” But the fact is that such an attitude is based upon unrealistic approach. It is true that Islam has forbidden Muslims from suspecting others or prying into their affairs, but at the same time the need of it cannot be denied in certain cases. This need, too, is felt because of urgent religious considerations. Hence the need of such investigation and inquiry is felt in the case of the Ahadith also. It is said that even among upright persons in early times there was a class of persons who considered the making of the Ahadith a matter of virtue and devotion and to frame them in respect of the excellence of the Prophet (sallallaahu alayhi wasallam). As the number of transmissional links began to record a sharp increase in course of time, their critical assessment also began to correspondingly increase in intensity.
It goes to the credit of Bukhari that, despite the rigid principles he has adopted in assessing the transmissional chain, he has not used the words kadhdhab (liar) and wadda’ (fabricator) as the other muhaddithin are won’t to. On the other hand this is very circumspect in this regard. Whenever he considers refutation absolutely essential, he uses the expression munkir al-hadith (negator of the Hadith). With regard to calumny also Bukhari has exercised the utmost circumspection and his abstinence in this regard is proverbial. He used to say that on the Doomsday, he would not be brought before the Bar of Judgement on this count. His remark in this behalf is worth reproducing.
Ever since I learned that calumny is forbidden; I have not resorted to it.
With the same loftiness of spirit he remarks:
Whenever I call anyone the negator of a Hadith I mean that the ascription of the transmissional chain to him is not justified.
Bukhari’s role regarding Asma’ al-Ruwat & ‘Ilal
This is why the knowledge of disqualifying factors in the Science of the Tradition is an important branch of study. In the terminology of the muhaddithin, ‘Illat is a discrepancy which impairs the soundness of a hadith. It carries special importance with regard to the study of the Ahadith besides other Sciences of the Tradition because it requires a discerning intellect and prodigious memory to trace out the mutual intercourse of the narrators, their dates of birth and death, their familial names and titles, their credibility and reputation, and ensure that the words employed in a particular Hadith through different channels, are fully preserved. Bukhari’s skill in this particular field has a distinct character of its own.
Hafiz Ahmad bin Hamadan has mentioned that he met Bukhari during the funeral prayers of ‘Uthman Abu Sa’id bin Marwan. There Imam Muhammad bin Yahya Dahli put questions in respect of the asma’ al-rijal (Names of the members of the transmissional chains) and the ‘Ilal  of the Ahadith. Bukhari replied instantly all the questions as if he was uttering Qul hu Allah . No better acknowledgement of Bukhari’s achievement is forthcoming than Tirmidhi’s admission that a large part of what he has written about the transmissional chain, narrators, history and all the ‘ilal he has indicated, have been derived from Bukhari’s work.
IMAM BUKHARI’S RANK IN TRADITION SCIENCE
Bukhari was very careful in respect of his works and loaned them only to the people he could trust. Once a person happened to mention a Hadith which gave rise to the suspicion of tadlis upon Bukhari, that is he had concealed one weak link in the transmissional chain. Bukhari replied that in order to obviate such a suspicion, he had relinquished more than ten thousand Ahadith reported by a particular muhaddith. Therefore, such a suspicion about him was neither justified nor warranted. The author of the Fath al-Bari has narrated a remarkable incident reflecting Bukhari’s circumspection. During his studentship Bukhari has to sail in a boat on a river. He had a thousand ashrafis (gold coins) in his possession. He was joined by someone who also boarded the boat and met him very reverentially, and gradually developed cordial relations so that Bukhari happened to mention to him about the money he had with him. One morning  the man began to raise hue and cry, saying that his bag containing one thousand ashrafis was missing. The passengers began to be searched, and Bukhari, appraising the situation, threw the bag into the river. The Imam’s belongings were also searched but the money could not be found. Thereupon everyone began to reprimand the accuser who was made to contrite. When the journey was over the man asked Bukhari about the bag of money. Bukhari replied that he had thrown it away into the river. When the man asked him why he thought it necessary to jettison it into the river and sustain such a big loss, Bukhari said, “All my life I have spent collecting and compiling the Ahadith of the Holy Peophet (sallallaahu alayhi wasallam) and my intregrity has assumed proverbial proportions. How could I afford to lose the far greater wealth which I have acquired against my life’s blood by acquiring the taint of a theft?.”
 The Hadith in respect of the narrator of which there exists some misgivings are called ma’lul. It is extremely difficult to detect such a Hadith and only a very accomplished connoisseur who possesses a very penetrating intellect, sharp memory and complete mastery over the authorities and text of the Traditions and knows the ranks of the narrators can spot it out. ‘Ali bin Madini, Ahmad bin Hanbal, Imam Bukhari, Ya’qub bin Abi Shaybah, Abu Hatim, Abu Dhar’ah, Darqutni and many other muhaddithin have discussed the matter at length.
 Hafiz Ibn Hajr has also described several such incidents. Qul hu Allah are the proverbially cryptic initial words of the Qur’anic Surah al-Ikhlas (112) meaning: “Say: He is Allah, the One.”
 This would imply that the journey was lengthwise and not across the river.