Fabrication of hadith (wad' al-hadith)

Hadith forgery arose after the Arbitration and the killing of Imam 'Ali, when the parties split and each sought to back its claim from Qur'an and Sunna; the Qur'an's many memorizers made tampering with it impossible, so they turned to the Sunna and added to it ¹. Its causes: the political factions, the zanadiqa enemies of Islam, the Shu'ubiyya, storytellers and preachers, currying favor with rulers, and the madhhab and kalam disputes ². The muhaddithun set the signs of fabrication in isnad and matn — feeble wording, corrupt meaning, contradiction of certain texts — and Ibn al-Qayyim held that spotting a forgery without consulting the isnad belongs only to one steeped in the sound Sunna.