Tahdhib al-Ahkam is a hadith collection, by the famous Twelver Shi'a hadith scholar Abu Jafar Muhammad Ibn Hassan Tusi, commonly known as Shaykh Tusi. This work is included among Twelver The Four Books of Shia Islam.
Tahdhib al-Ahkam could be translated as "The Refinement of the Laws (as Discussed) in Terms of the Explanation of the Sufficiency".
The original intention of al-Tusi had been to write a commentary on al-Muqni'a of al-Mufid. However, he makes it clear in his introduction that his work would only concern the practical regulations for carrying out the sharia, the holy law of Islam. He said: "I went first to the chapter which was connected with ritual purity (tahara), leaving aside the (chapters) which preceded it, which were about the Unity of God (tawhid), Justice (adl), Prophethood (nubuwwa) and the Imamah, because the explanation of these would be too lengthy, and also because it was not the intention of this book to elucidate the principles of religion (al-usul).
In his introduction, al-Tusi makes it clear that the principal motive for writing this work and limiting it to the furu', was the great differences which were arising in Shia traditions. He mentions that these differences were being used against the Shia by their opponents as an argument against the truth of Shia beliefs. Al-Tusi set himself the task of analysing the traditions concerned with furu', explaining which traditions were deficient and reconciling apparent contradictions in sound traditions. He used al-Mufid's al-Maqni'a as the basis for this task. However, he did not only deal with the traditions used in al-Muqni'a; he analysed many more traditions which he included at the end of various sections, appendices of traditions not mentioned by al-Mufid, which he also discusses.
Shi'a Muslims regard this book as among the most reliable Hadith collections. Thus, the book is included in The Four Books of the Shi'a, together with Al-Kafi, Al-Istibar and Man la yahduruhu al-Faqihm. However, all hadith must be individually examined and no book other than the Quran is considered sahih.