Al-Marwazee (ra) said: 'I departed to go see Al-Karaabeesee, at the time when he was of good standing (i.e. he hid his innovations), for he used to defend the Sunnah and demonstrate support for Abu 'Abdillaah (Ahmad Ibn Hanbal). So I said to him: 'Indeed, the people wish to present this book Al-Mudalliseen to Abu 'Abdillaah. So It is best that you regret what you wrote or I will inform Abu 'Abdillaah.' So he said to me: 'Indeed, Abu 'Abdillaah is a righteous man, a man of his status has been granted the ability to attain the truth. And I am very pleased that my book will be presented to him. Abu Thawr, Ibn 'Aqeel and Hubaish have already asked me to destroy this book, but I refused and said to them: Rather, I will intensify my promotion of it!' So he persisted in that and he refused to go back on what he wrote in it. So I brought the book to Abu 'Abdillaah, while he was unaware of who authored it. And in the book, there was disparaging of Al-A'amash and support in favor of Al-Hasan Ibn Saalih. And there was written in it: 'If you say that Al-Hasan Ibn Saalih took the views of the Khawaarij, then this Ibn Az-Zubair is truly the one who has accepted the views of the Khawaarij!' So when it was read to Abu 'Abdillaah (ra), he said: 'This book compiles, for those who oppose (the Sunnah), that which they are not able to use as substantial proof. Warn others about this book!' And he renounced it.'" [28]

Ibn Rajab (ra) continued:

"Large groups of innovators from among the Mu'atazilah and others have gained supremacy in attacking the scholars of hadeeth, through his book (Al-Mudalliseen), such as Ibn 'Ibaad As-Saahib and his likes. Likewise, some hadeeth scholars transcribed from it, its schemes to discredit Al-A'amash (ra) and others. This was perhaps because the condition of the book was not known to him, as was the case with Ya'qoob Al-Fasawee and others.

As for the scholars of Ahl-us-Sunnaah wal-Jamaa'ah, then indeed they only mentioned the defects of the hadeeth in order to advise others in the Religion, to preserve and safeguard the Sunnah of the Prophet (sallallaahu alayhi wasallam) and to identify what befell the narrators of hadeeth from error, forgetfulness, and weakness. It is not required that this (criticizing of narrators) be done for discrediting the non-defective ahaadeeth. Rather, the correct ahaadeeth, according to them, were strengthened by that, due to their being free of defects and errors. Thus, these individuals are the true scholars who are knowledgeable of the Sunnah of the Messenger of Allaah (sallallaahu alayhi wasallam). They are the great intellectual critiques that review and examine the hadeeth skillfully and proficiently, with true criticism as opposed to false criticism."

Al-Haafidh Ibn Rajab (ra) said:

"When a statement would reach the Salaf that they would reject, they would say: 'This person has lied.' This example is taken from the statement of the Prophet (sallallaahu alayhi wasallam): 'Abu As-Sanaabil has lied', when news reached him (sallallaahu alayhi wasallam) that he issued a ruling that a woman whose husband passed away, while she was pregnant, was not permitted to relocate until fourteen months had passed by, due to her pregnancy.

And indeed the righteous scholars have gone to great lengths in forsaking the weak treatises of some scholars. And they have refuted them with the highest degree of refutation, as Imaam Ahmad (ra) used to censure Abu Thawr and others for weak treatises they had written specifically, apart from their other works. And he went to great extremes in refuting them.

This is the ruling for the matters on the outward. As for the inner affairs, then if ones objective in doing that (criticizing) is to clarify the truth and so that the people will not be deceived by the works of those who erred in their writings, then there is no doubt that this individual’s aim will be rewarded. And his doing this, along with this intention, causes him to fall into the category of being from those who show sincerity to Allaah, His Messenger and the scholars of the ummah and its common folk. And it is the same whether the one who clarifies the mistake is young or old. Thus, he has a good example in Ibn 'Abbaas in refuting written works of the scholars…"