Yahya ibn Sharaf al-Nawawi was born in Muharram 631 AH (October 1233 CE) in Nawa, near Daraa in Syria, and moved to Damascus at eighteen to study. In 665 AH (1267 CE) he was appointed head of the Ashrafiyya Dar al-Hadith in Damascus, a post he held until his death in Nawa in 676 AH (1277 CE), in his mid-forties; he was buried there. A Shafi'i jurist, he wrote prolifically in that short life — among his other works are Riyad al-Salihin, a commentary on Sahih Muslim known as Al-Minhaj, al-Majmu' Sharh al-Muhadhab, Minhaj al-Talibin, and Kitab al-Adhkar.
Al-Arba'in al-Nawawiyyah continues an older tradition of "forty hadith" (arba'iniyyat) collections, whose premise is a hadith promising those who preserve forty hadith concerning the religion a place among the scholars on the Day of Judgment — a hadith most critics classify as da'if (weak) in its own right. The first such collection, now lost, is credited to Abdullah ibn al-Mubarak (d. 797 CE); many scholars made their own after him. Al-Nawawi selected hadith he judged sound, mostly from [[BUK|Sahih al-Bukhari]] and [[MUS|Sahih Muslim]], each illustrating what he called a "great foundation" (qa'ida azima) of the religion — and despite the title, the collection as it stands holds forty-two. It became the single most-read example of the genre, drew dozens of commentaries, most famously Ibn Rajab al-Hanbali's Jami' al-'Ulum wal-Hikam, and is counted among the most widely read works in Sunni Islam after the Qur'an itself.
The Arabic text here is the classical matn, in the public domain. Beneath it in the reader sits an English translation, drawn from the fawazahmed0/hadith-api's eng-nawawi edition and aligned hadith-for-hadith with the Arabic so the two can be read as a pair — the same companion arrangement this corpus uses for [[BUK|Sahih al-Bukhari]], [[MUS|Sahih Muslim]], [[ABD|Sunan Abi Dawud]], [[TIR|Jami` at-Tirmidhi]], [[NAS|Sunan an-Nasa'i]], [[IBM|Sunan Ibn Majah]], [[MAL|Muwatta Malik]], and its Qur'an translations. Which published English translation that file itself descends from has not been pinned down on this corpus's side, which is why its licence is marked under review rather than public domain outright; the Arabic above it carries no such uncertainty.