to the judge’s having a single vetted informant who acquaints him with the standing of the witnesses; in such matters he may rely on that man’s word alone. Should the judge already know that a given person is upright, he may dispense with any inquiry and rely on his own knowledge. Likewise, if the judge is aware of something about a witness that legally bars the acceptance of his testimony, he may not accept the commendation of those who declare him upright; instead, he must refrain from issuing judgment, keeping the matter discreet and conducting the proceedings with propriety.

Ibn al-Mawwāz has stated that the judge should nevertheless accept the commendation offered by certifiers for someone whom the judge himself knows to be otherwise, on the grounds that rejecting their attestation would amount to ruling on the basis of his personal knowledge, and a judge, he says, does not rule by what he personally knows. This view, however, is untenable, for there is unanimous agreement that when a judge knows a person to be neither upright nor acceptable, he may not admit that person’s testimony; the same prohibition applies to accepting commendation on his behalf.

No one may vouch for another on the basis of a fleeting acquaintance. One must have verified the person’s integrity and trustworthiness over a lengthy period, testing him through close neighborhood in town, commercial dealings, and travel companionship. This, too, is reported from ʿUmar, may Allah be pleased with him.