the imams? What is the basis for treating it as authoritative evidence? May someone who calls others to religious innovation and argues in its favour be shielded from exposure, or is there a stronger obligation to testify against him so that people may beware of him? What defines the religious innovation by which a person is counted among the adherents of deviant beliefs?

He replied:

Matters that impugn the integrity and religious commitment of a witness or anyone else may be testified to when the person testifying knows of them through widespread reports. This constitutes a legally valid challenge to that person’s integrity, as groups of Mālikī, Shāfiʿī, Hanbalī and other jurists have explicitly stated in their larger and smaller works. They expressly state that, when a person’s integrity is challenged on disqualifying grounds, the challenger may base his criticism on what he has heard from that person or witnessed, and what has become widely reported.

I know of no disagreement among people concerning this. All Muslims in our time testify to the integrity and religious commitment of such people as ʿUmar ibn ʿAbd al-ʿAzīz, al-Hasan al-Basrī and others like them, on grounds known to them only through widespread reports. Likewise, they testify to the injustice and religious innovation of such people as al-Hajjāj ibn Yūsuf, al-Mukhtār ibn Abī ʿUbayd, ʿAmr ibn ʿUbayd, Ghaylān al-Qadarī, ʿAbd Allāh ibn Sabaʾ the Rāfidī, and others like them, on grounds known to them only through widespread reports.

An authentic report from the Prophet—may Allah bless him and grant him peace—relates:

A funeral procession passed by him, and those present spoke well of the deceased. He said, “It is assured.” Another funeral procession passed by him, and they spoke ill of the deceased. He said, “It is assured; it is assured.”

They asked, “Messenger of Allah, what do you mean by saying, ‘It is assured; it is assured’?”

He replied, “You spoke well of the first deceased person, so I said that Paradise was assured for that person. You spoke ill of the other deceased person, so I said that the Fire was assured for that person. You are Allah’s witnesses on earth.”

This applies when the purpose is to declare someone a sinner in order to disqualify him as a witness and from exercising authority.