How can a fabricated hadith with an authentic-looking, forged chain of transmission be distinguished from a real hadith, especially if the fabricator is skilled at constructing the chain with seemingly upright and interconnected narrators? And is the memorization of hadith through successive authorizations (ijazat) the solution to counter this falsification?

There is no fear today of fabricating seemingly authentic chains of narration (asanid) for fabricated texts (mutun), because the authenticity of a report does not solely depend on the apparent soundness of its chain and the trustworthiness of its narrators. Rather, it is also conditional upon its freedom from anomaly (shudhudh) and defect (illah). Allah has preserved the Sunnah by inspiring the imams of Hadith to meticulously compile and transmit Hadith works. Reliance is no longer placed on late chains of narration, but on accurately verified copies of the Sunnah's established collections. If such an event (fabrication) were to occur, it would be easy to refute, for the mere claim of a chain and report not found in the established collections of the Sunnah is sufficient to judge its claimant as a liar.

Distinguishing fabricated chains of narration and unsound texts is achieved by examining the narrators and studying their transmissions. The imams of Hadith meticulously tracked narrators, differentiating the trustworthy from the weak and the liars. They collected all reports related to a narrator and compared them to determine whether the narrator was unique in his transmission, agreed with trustworthy narrators, or contradicted them. Thus, the way to discern the authentic from the unsound is to subject the narration to the microscope of criticism, by examining the statements of the imams regarding the narrators of its chains and comparing the narration with others, in accordance with the principles of Hadith criticism.