What are the 7 ahruf (dialects) of the Qur'an?

In a Nutshell: The Qur’an was revealed in 7 different dialects as mentioned by the Prophet (saw) himself, and the various Qira’aat are simply different mixes of these 7 dialects which most Muslims around the world recite today. Regarding the issue of the Ahruf and the Qira'aat, here is a simple explanation. Allah says in the Qur’an: “We have revealed the (Qur’an) and We will surely protect it...” No human can replicate the style of the Qur’an, and it could not have come from a human being otherwise countless people would have replicated it, and therefore it is a miracle. The Ahruf (singular: “Harf”) Ahruf translates to "letters," but actually means "dialects." All 7 Ahruf were revealed by Allah to the Prophet (saw). All of them are a single Qur’an. None of the variations of the words in each of the Ahruf are contradictory, rather they add richness and detail to the Qur'an. Again, they are all from Allah. Some examples of the variations among the Ahruf: In Surat Al-Fatiha, in the verse that says “The Owner of the Day of Judgement,” one of the Ahruf reads as "Maaliki Yawm Ad-Deen" مالك يوم الدين (meaning "Owner of the Day of Judgement"), and another reads as "Meliki Yawm Ad-Deen" ملك يوم الدين (meaning "King of the Day of Judgement") In Surat An-Noor, in the verse that speaks of “In Houses (Masajid) that were raised to remember Allah,” one of the Ahruf reads as “Buyut” بُيوت, and another reads as “Beeyut” بِيوت, which is simply a difference in dialect among the various Arab tribes and both have the same meaning. In Surat Al-Baqarah, in the verse near the beginning that says “Those who disbelieve, it is equal for them if you warn them or don’t warn them, they won’t believe,” one of the Ahruf reads as “A-Anthartahum” أأنذرتهم, and another reads as “Aaanthartahum” أَنذرتهم (with an elongated “a” and without adding a second Hamza), which are also two different dialects among the Arab tribes and have the same meaning. In Surat Al-Hujurat, in the verse that says “If a Fasiq comes to you with news, verify it,” one of the Ahruf reads as “Fatabayyanu” فتبينوا (verify it), and another reads as “Fatathabbatu” فتثبتوا (establish proof for it). Here is an example of two different words, but with the same meaning, and both were revealed by Allah to the Prophet (saw). And there are many more examples, all following similar patterns, and all given to us by the Prophet (saw) during his lifetime. How were the Ahruf revealed? The Ahruf were not revealed as 7 separate “books,” rather they were all revealed together as a single Qur’an, and each Harf was used depending on the situation when it was best suited. The Prophet (saw) would read according to one Harf in one situation and according to another Harf in another situation, and did not identify a specific “set” of each of the Ahruf or name them. The situation where the Ahruf were used separately most often was when he would send someone to teach the Arabs in a particular region the Qur’an, and would send him with one of the Ahruf that was best suited for the dialect in that region. So, the differences between the various Ahruf were not a separating factor, but rather a unifying one to add detail and to ease recitation and memorization for the various Arab tribes with different dialects. It is permissible to mix and match between the various Ahruf (and the Sahaba did mix them, as you will see in the next section). You can read - in the same verse - one word according to one Harf and another word according to another Harf. They are all the same Qur’an, so we don’t treat them as separate. Qira’aat (singular is “Qira’a”) Qira’aat translates to “readings.” The Qira’aat are different “mixes” of the 7 Ahruf. The Qira’aat were entire copies of the Qur’an written down on various objects, such as parchment, palm leaves, wood, bones, and so on. All the Qira’aat were from the Sahaba themselves originally, which was their own “mix” of the 7 Ahruf they learned from the Prophet (saw). As the years passed, the names of the Qira'aat changed in reference to the most prominent person behind that Qira'a. There are 10 definitely authentic Mutawatir Qira’aat. The rest are not Mutawatir and are not relied upon (a long story I’m not going to get into here). Why not just use the original 7 Ahruf? Why use these Qira’aat? The problem is, there are no narrations where the Prophet (saw) specifically identified to us the different Ahruf separately, so we only know about the details of the differences between the various Ahruf from the Qira’aat. To make this clearer: The way we know that there are 7 Ahruf is because the Ahadith mention the 7 Ahruf: إن هذا القرآن أنزل على سبعة أحرف “The Qur’an was revealed in 7 Ahruf” (Bukhari) But the way we know what the differences are between the 7 Ahruf is by looking at the Qira’aat. The things people think are “problems” in the Qira’aat, but are not actually problems: There are a wide variety of examples, but here are just a few to make the point clear: In Surat Al-Baqarah, the correct verse says “Protect your prayers and (especially) the middle prayer, and stand to Allah in obedience” حافظوا على الصلوات والصلاة الوسطى وقوموا لله قانتين but the Mus-haf (physical written copy of the Qur’an) of Ibn Mas’ood (ra) says حافظوا على الصلوات والصلاة الوسطى صلاة العصر “Protect your prayers and (especially) the middle prayer, the prayer of Asr.” Some people were confused and thought that the last part about Asr was a verse, but it is almost certainly a note made by Ibn Mas’ood (ra), where he might have asked “what is the middle prayer?” and the Prophet (saw)said “the prayer of Asr,” and then Ibn Mas’ood (ra) wrote that down as a note next to the Ayah. In the Mushaf of Ubay bin Ka’b (ra) we find the words “If the son of Adam were given two valleys of gold…” لو كان لابن آدم واديين من ذهب... and this was called “Surat Al-Qunoot” by someone who was attempting to document the different Qira’aat, but again it is quite obvious that this was a Hadith that was written down on the same object that the Qur’an was written on – likely as the Prophet (saw) was reciting an Ayah, he mentioned that Hadith while explaining the Ayah and the Sahabi wrote it down on the same parchment or piece of wood or whatever. In another Mus-haf, we find the words “O Allah, it is You whom we worship, and to you we pray and prostrate, and to you we run and seek help.” In Arabic: اللهم إياك نعبد، ولك نصلي ونسجد، وإليك نسعى ونحفد and this was called “Surat Al-Hafd” by someone who attempted to document the different Qira’aat, but once again it is very obvious that this was simply a du’a – either the Sahabi’s own du’a that he wrote down, or possibly a du'a the Prophet (saw) said or taught that the Sahabi noted down on the same object. The important thing to understand here is that back then they did not have books like we have today. Their “books” were basically various unbound piles of parchments and palm leaves, etc, and sometimes they would write down notes or du’as or Ahadith on the same objects that they wrote the Qur'an on. Conclusion There is more to this topic, but most of it is not relevant. What is relevant is to know that the Qur’an was revealed in 7 different dialects as mentioned by the Prophet (saw) himself, and the various Mutawaatir Qira’aat are simply different mixes of these 7 dialects. We all read from these Qira’aat during our prayers all over the world, and there is no doubt in the authenticity of what we read. The style of the Qur’an is a miracle that cannot be replicated, and it is impossible for a human being to have composed it, otherwise countless people would have replicated its style by now.