introduction
[Translation of Imam Nawawi's original introduction in Matan al-Arba'in]

In the name of Allah, Most Gracious, Most Merciful.

Praise be to Allah, Lord of the worlds, eternal Guardian of the heavens and the earths, Ruler over all creatures, who sent to responsible beings the Messengers - upon whom be His blessings and peace - that they might bring them guidance and make clear to them the Shari'ah (Law). Him do I praise for all His favours, and from Him do I beg increase of His kindness and His generosity. Also I bear witness that our Master Muhammad is His servant and His Messenger, His Beloved and His friend, the most excellent of created beings, who was honoured by being given the mighty Qur'an, and by being given the Sunnah (right practices) which enlighten those who seek to be directed in the right way, who is distinguished for the all-embracing wisdom of his discourse, and for his perseverance in the worship of Allah. May Allah's blessing and peace be upon him, and upon the rest of the Prophets and Messengers, upon the families of them all, and upon all the believers.

To proceed: It has been transmitted to us on the authority of Ali bin Abi Talib, Abdullah bin Masud, Muadh bin Jabal, Abu al-Darda, Ibn 'Umar, Ibn Abbas, Anas bin Malik, Abu Hurairah and Abu Sa'id al-Khudri, may Allah be pleased with them all, through many chains of authorities and in various versions, that the Messenger of Allah, sallallahu 'alayhi wasallam, said:

"Whosoever memorises and preserves for my community forty hadith concerning matters of this religion, Allah will resurrect him on the Day of Judgment in the company of jurists and religious scholars."

In another version, this Hadith reads:

"Allah will resurrect him as a jurist and religious scholar."

In the version of Abu al-Darda, it reads:

"On the Day of Judgment I shall be an intercessor and a witness for him."

In the version of Ibn Mas'ud, it reads:

"It will be said to him: Enter the Garden (paradise) by whichever gate you wish."

In the version of Ibn 'Umar, it reads:

"He will be recorded in the company of the religious scholars and will be resurrected in the company of the martyrs."

Scholars of Hadith are agreed that it is a weak hadith despite its many lines of transmission.
The religious scholars, may Allah be pleased with them, have composed innumerable works in this field. The first one I knew of who did so was Abdullah bin al-Mubarak, followed by Ibn Aslam al-Tusi, one who was devoted to his Lord, then al-Hasan bin Sufiyan al-Nasai, Abu Bakr al-Ajurri, Abu-Bakr Mubammad bin Ibrahim al-Asfihani, al-Daraqutni, al-Hakim, Abu Nuaim, Abu Abd al-Rahman al-Sulami, Abu Saeed al-Malini, Abu Uthman al-Saboni, Abdullah bin Muhammed al-Ansari, Abu Bakr al-Baihaqi, and countless others, both ancient and modern.

I have asked Allah Almightly for guidance in bringing together forty hadith in emulation of those eminent religious leaders and guardians of Islam. Religious scholars are agreed it is permissible to put into practice a weak hadith if virtuous deeds are concerned; despite this, I do not rely on this hadith but on the Prophet, sallallahu 'alayhi wasallam, having said the sound hadith:

"Let him who was a witness among you inform him who was absent"

and on his, sallallahu 'alayhi wasallam, having said:

"May Allah make radiant [the face of] someone who has heard what I have said, has learnt it by heart and has transmitted it as he heard it".

Furthermore, there were some religious scholars who brought together forty hadith on the basic rules of religion, on subsidiary matters, or on jihad, while others did so on asceticism, on rules of conduct or on sermons. All these are godly aims - may Allah be pleased with those who pursued them. I, however, considered it best to bring together forty hadith more important than all of these, being forty hadith which would incorporate all of these, each hadith being one of the great precepts of religion, described by religious scholars as being "the axis of Islam " or "the half of Islam" or "the third of it ", or the like, and to make it a rule that these forty hadith be [classified as] sound and that the majority of them be in the sahihs of Al-Bukhari and Muslim. I give them without the chains of authorities so as to make it easier to memorise them and to make them of wider benefit if Allah Almighty wills, and I append to them a section explaining abstruse expressions.

Note: Every person wishing to attain the Hereafter should know these hadith because of the important matters they contain and the directions they give in respect of all forms of obedience, this being obvious to anyone who has reflected upon it. On Allah do I rely and depend and to Him do I entrust myself; to Him be praise and grace, and with Him is success and immunity [to errors].