How can weak hadiths be distinguished from authentic ones, especially with the prevalence of hadiths such as, "Its beginning is mercy, its middle is forgiveness, and its end is emancipation from the Fire," and, "A supererogatory act is rewarded as an obligatory one, and an obligatory act is rewarded as seventy obligatory ones," despite their weakness?

The aforementioned hadith is weak, but it is permissible to act upon it regarding the virtues of deeds, encouragement, and deterrence, provided certain conditions are met. This is a lengthy hadith narrated by Ibn Khuzaymah from Salman (may Allah be pleased with him), and Al-A'ẓamī deemed it weak due to the weakness of one of its narrators. The judgment on a hadith's authenticity or weakness is based on probability, relying on the rules established by scholars to distinguish between different grades of hadith. There is no need for concern, as Allah has appointed brilliant scholars for this knowledge who distinguish its authentic from its weak, and the Prophetic hadiths are preserved just as the Book of Allah (the Qur'an) is preserved. The Hufaz (hadith masters) have authored books specifically for authentic hadiths, and others that collect both authentic and non-authentic, all with chains of narration through which a judgment can be made on the hadith.