فواتح السور
fawātiḥ al-suwar
The letters of the Arabic alphabet that stand at the head of a number of surahs.
What it means
Twenty-nine surahs of the Quran open with one or more letters of the Arabic alphabet, read out by their names and not as words. The first is surah 2, which begins Alif Lām Mīm (2:1). Others include Yā Sīn (36:1), Qāf (50:1) and Nūn (68:1). In all, fourteen different letters are used, alone or in combination. The Quran’s reciters pronounce them letter by letter.
Their meaning is not settled. Some commentators say they are among the matters that God alone knows. Others propose that they point to the fact that the Quran is built of the very letters the Arabs used, and yet cannot be matched (compare 2:23). Many of these surahs go on at once to speak of the Book’s revelation. The term is also given as al-ḥurūf al-muqaṭṭaʿa, the disjoined letters.
Often misunderstood as
Called “mysterious letters” as if a hidden code; scholars treat them as an opening feature of the revelation whose sense is disputed or known to God.
Term and Arabic as listed in Ismail al Faruqi, Toward Islamic English (International Institute of Islamic Thought, 1995), p. 48, listed as FAWĀTIḤ AL SUWAR. The definition is restated here.