Modern scholarship has accepted the 'backgrowth of isnāds' in the early hadīth tradition, but this phenomenon did not occur without controversy among classical Muslim scholars. Hadīth critics were aware that material was being pushed back to the Prophet, a phenomenon they approached through the lens of ziyāda (addition). By examining works devoted to criticizing hadīth narrations ('ilal) from the 3rd/9th to the 8th/14th centuries, we will see that the original non-Prophetic versions of many hadīths survived alongside their Prophetic counterparts well into the 5th/11th century. More importantly, certain hadīth scholars from the 3rd/9th to the 7th/13th centuries believed that Prophetic reports in the canonical hadīth collections were actually statements of other early Muslims. The position of these critics, however, was marginalized in the 5th/11th century, when mainstream Sunni jurists chose to accept the Prophetic versions categorically. Although the jurists' position became dominant in Sunni Islam, criticism of the backgrowth of isnāds has continued in the work of select hadīth scholars until today.