Reference: Siyar A’laam an-Nubalaa – Volume 7, Page 400
Yoosuf as-Saa.igh narrated that [when] the people of innovation raised their heads and began debating [in matters of the religion], al-Mahdee – the ‘Abbaasid ruler – ordered the[m] people to refrain from talking, and not to engage in speaking [in matters of the religion without sound knowledge].
