Islamic scholars, motivated by a tradition from the Prophet Muhammad, which promises Divine Rewards for scholars who collect forty traditions, compile hadith narrations in groups of forty.
This text is the Second revised edition of a detailed commentary on 40 selected traditions narrated through the Prophet (S) and his Ahl al-Bayt (a) on topics of ethics and spirituality.Thirty-three of the hadith Imam Khomeini selected pertain to Islamic ethics, including acts which bring reward or punishment. The other seven focus on beliefs and concepts related to the Theology of Twelvers. The very first hadith is on Jihad of the self that aims at self-improvement elevating oneself through self-control and self-discipline and shun pride (kibr), ostentation/show-off (riya), self-conceit (ujb), envy (hasad), love of the world, anger (ghadhab), prejudice (asabiyyah) and hypocrisy (nifaq). In his collection, Imam Khomeini has included the ahadith that help us elevate our status through intellect (tafakkur), trust in God (tawakkul), man’s natural instincts to seek out God, meeting with God and to fear (khawf) Him. 

The original work in Persian, recently published under the title “Arba’in, ya chihil hadith” was written by Imam al-Khumayni forty-six years ago and was completed in the month of Muharram 1358 (April-May, 1939). The manuscript of this work, together with that of two other unpublished works of the author, Sharh Du’ae sahar, and Adab al-salat, were recovered from the library of the late Ayatullah Akhund al-Hamadani. All the three works have now been published.