‘Ilal al ḥadīth or T’alīl-e ḥadīth is most important and critical sciences of hadith, especially for the judgment of the chain of hadith and its text. It also provides principality foundations to make impracticable hadith. It is said that T’alīl-e ḥadīth is knowledge of deciding any hadith for being it practicable or impracticable. So, in medieval, all researches about this science in a specific method are a major subject of this study. In this case, the scholars of the sub-continent and their research regarding T’alīl-e ḥadīth is analyzed by discussing their approaches and affinities subtended to ancient scholars and Moḥaddīthīns, so that we may be able to acknowledge the foundation laid by them in sectarianism with the passage of time and its impact on the history of hadīth & Islamic jurisprudence. T’alīl e ḥadīth is the subjective knowledge of hidden defects regarding hadith especially the chain of narrators. These hidden defects are called ‘illat in Arabic and prophetic sayings in etymology. There are two necessary characteristics in ‘illat; first, it must be hidden and second, it must be dubious. If one of these conditions is not found, the hadith will be stable for practice. This topic provided a good source to the way to acknowledge the services and research of famous scholars of the sub-continent i.e. Moḥaddīthīns and jurists. In this regard, the research question was: is there any contribution of these scholars of sub-continent in the science of ’Ilal e ḥadīth? And what is their addition to this knowledge among the ancient researches of Muslim Scholars? The researcher finds that in the sub-continent, only twelve books were found in which discourses of T’alīl e ḥadīth were discussed. Some of them are reference books, some are edited and only one manuscript is about the explanation of ancient scholar imam Tirmdhī’s book. And the second aspect of this science is found in books of principles of ḥadīth written by scholars in the sub-continent but too much less quantity.