ما هي الأحاديث التي يتم الأخذ بها والاستدلال بها شرعًا؟

The hadith (definition) that must be adopted and used as evidence are the accepted hadith, which are: the sahih (definition) (authentic) and the hasan (definition) (good). As for weak and fabricated hadith, it is not permissible to use them as evidence for a legal ruling. The scholars have agreed upon the obligation of acting upon the sahih hadith once it is confirmed to be from the Prophet, peace and blessings be upon him, and the impermissibility of relying on weak hadith in matters of rulings and beliefs. It is not permissible to act except upon that which is proven to be authentic (sahih) or good (hasan), and this is done by the knowledge of the hadith specialists who are experts in knowing its chains of transmission (asanid) and its narrators (rijal).