An-Nashr (), which is 1014 lines on the ten major reciters in great detail, of which he also wrote a commentary. Religious Obligation Knowledge of the actual tajwīd rules is a community duty (farḍ al-kifāya). There is a difference of opinion on the ruling for individuals. Dr. Shadee Elmasry states that it is an individual obligation (farḍ al-'ayn) on every Muslim to recite the opening chapter of the Qur'an (al-fatiha) with correct tajwīd, though they do not need to know the terms and definitions of the rules themselves. Sheikh Zakariyya al-Ansari stated that it is sinful to recite in a way that changes the meaning or changes the grammar. If it does not change these two things, then it is not sinful, even if it is a clear error. Qur'an and Hadith on Tajwīd The central Quranic verse about tajwid is verse 73:4: "...and recite the Qur'an with measured recitation." The word (), as used in this verse, is often also used in hadith in conjunction with its command. It means to articulate slowly, carefully, and precisely. Abu Dawud's hadith collection has a chapter heading titled "Recommendation of (reciting with) in the Qur'an." It begins with the narration: "The Messenger of Allah peace and blessings be upon him said: One who was devoted to the Qur'an will be told to recite, ascend and recite carefully ( ) as he recited carefully when he was in the world, for he will reach his abode when he comes to the last verse he recites (Sunan Abi Dawud 1464)." This narration describes the importance of the manner of recitation and its positive effects in the afterlife. The next narration describes the importance of prolongation ( ): "Qatadah said: I asked Anas about the recitation of the Qur'an by the Prophet, peace and blessings be upon him. He said: He used to express all the long accents clearly () (Sunan Abi Dawud 1465)." This narration also shows that even the companions of the prophet used some terms which are still used today in rules. Arabic alphabet and grammar The Arabic alphabet has 28 basic letters, plus hamzah (). The Arabic definite article is al- (i.e. the letter alif followed by ). The in al- is pronounced if the letter after it is (, lunar), but if the letter after it is (, solar), the after it becomes part of the following letter (is assimilated).