“…that a trustworthy person narrates upon the authority of another trustworthy person and so on until they reach the Prophet - صلى الله عليه وسلم. Allah has specified the Muslims with this, in contrast to all other religions, and He has allowed it to remain with them, renewed over the ages.”
Al Hafidh Abu ‘Alee stated: “Allah specified this Ummah with three things that He never gave anyone before them; al Isnaad, al ‘Iraab, and al Ansaab.”
In recent times, foreign researchers have admitted the great accuracy and preciseness of the works of the people of Hadeeth, and have acknowledged the finesse of their endeavor. Historians have derived principles from the methods of the people of Hadeeth and have used them to verify the truthfulness of historical events. In these methods, they have found the finest principles in ascertaining the truthfulness of past events.
[The Methodology of Criticism in the Knowledge of Hadeeth: P.3]