Some deviant sects claimed that The Messenger of Allah sallalahu alaihi wa sallam was simply a person who delivered the Quran to the World. He was not an authority. Some claim he was only a ruler for his times and not a Prophet for all of mankind. While a third group after acknowledging his prophet-hood claim that his hadiths did not reach us in a reliable method therefore the hadiths have no authority in legislation.

Hazrat Shaikhul Islam Maulana Mufti Muhammad Taqi Usmani refutes all the above claims with strong and sound evidences. It is a must read for students of Hadith.

Download:
https://archive.org/details/TheAuthorityOfSunnahByMuftiTaqiUsmani