`Allamah Taj al-Din Ibn al-Subki says,
“One whose leadership and uprightness have been established, whose extollers and accreditors abound, and whose discreditors are rare, and there are circumstances indicating the reason for his discreditation – by way of partisanship to a school of thought or something else – we do not heed discreditation of him. We deal with him as upright; otherwise, if we were to open this door, and to start giving absolute precedence to discreditation, none of the Imams would remain for us unscathed, for there is no imam whom [some] maligners have not maligned, and in [whose malignment ] some fools have not destroyed [themselves].
Hafiz Ibn `Abdil-Barr composed a chapter, in his book on knowledge, about the verdict of scholars’ statements about one another. In it, he began with the hadith of Zubayr (may Allah be pleased with him) ascribed [to the Prophet (may Allah bless him and grant him peace)], “The malady of the nations before you has crept towards you : envy and hatred . . . .” And, he narrated through his isnad, on the authority of Ibn `Abbas (may Allah be pleased with him) that he said, “Listen to the knowledge of scholars, but do not affirm them against one another, for by He in whose Hand is my soul, indeed, they differ with one another more than the goats in a corral.”
And, on the authority of Malik ibn Dinar : he said, “Take by the sayings of the scholars and reciters in everything except their statements about one another.””
We informed you at the start that discreditation is not accepted from a discreditor – even if he details it – with regard to one whose [acts of] obedience [to Allah] outweigh his acts of disobedience, whose extollers [outnumber] his critics, and whose commenders [outnumber] his discreditors – if there are circumstances which [are such that] reason testifies that the like of them can incite [someone] to defamation of the one he is discrediting. [These circumstances can be] by way of fanaticism to a school of thought, or worldly vying such as may occur among rivals, or other [factors] besides those. So, we say, for example : the words of Ibn Abi Dhi’b about Malik are not to be heeded, nor [those of] Ibn Ma`in about al-Shafi`i, nor [those of] al-Nisa’i about Ahmad ibn Salih. [This is] because these are famous imams, [and so] the discreditor of them becomes comparable to one producing an obscure report [which,] if it were authentic, is such that there would be abundant motives [for others] to report it [as well, but since no such abundant reports exist], certainty is established about its untruthfulness.
Among that which should be investigated when [considering] discreditation is : the state of beliefs and differences in them, with regard to the disreditor and the discredited. Often, the discreditor may differ with the discredited in [peripheral issues of] doctrine, and discredit him because of that. This was alluded to by al-Rafi`i when he said, “It is imperative for the commendors [of narrators] to be free of rancor and partisanship to a school of thought, out of fear that that may incite them to discredit an upright individual, or to commend a transgressor, and [in fact] this has occurred for many of the imams.”
Shaykh al-Islam Taqiyy al-Din Ibn Daqiq al-`Id, in his book, “Al-Iqtirah” has indicated this, saying, “The reputations of the Muslims are one of the pits of the Fire [of Hell]. Two groups of people have stood at its brink : the hadith scholars and the judges.”
One of the examples of that which we have mentioned above is the statement of one of [the scholars] about al-Bukhari, “Abu Zur`ah and Abu Hatim forsook him on account of the issue of the Word [of Allah].” Alas, what a calamity!! Is it permissible for anyone to say Bukhari is to be forsaken, when he is [in fact] the bearer of the standard of this vocation, and the forerunner of Ahl al-Sunnah wa al-Jama`ah?
Among [the examples of this also] is the statement of one of the corporealists (Mujassimah) about Abu Hatim Ibn Hibban, “He was not very religious; we expelled him from Sijistan because he denied a limit for Allah.” Alas! I wish I knew who is more deserving of expulsion : one who considers his Lord limited, or one who declares His transcendence above corporeality!!
The examples of this abound.”
[al-Tabaqat al-Kubra, vol. I, p. 187]
Similarly, Hafiz Ibn Hajar reports, under the biographical entry for Muhammad ibn al-Muthanna,
“`Amr ibn `Ali was asked about [Muhammad ibn al-Muthanna and Bundar, whereupon he replied, “Two reliable individuals; everything is accepted from them except for that which they say about one another.”]
[Tahdheeb al-Tahdheeb, vol. IX, p. 427)]
[See also: “Fawatih al-Rahamut,” vol II, p. 154; “al-Raf` wa al-Takmil fi al-Jarh wa al-Ta`dil,” by M. `Abdul-Hayy al-Laknawi. ]