﴿ وَمِنۡہُمۡ أُمِّيُّونَ ﴾
(And there are among them Ummyyun people) meaning, among the People of the Book, as Mujahid stated. Ummyyun, is plural for Ummi, that is, a person who does not write, as Abu Al-`Aliyah, Ar-Rabi`, Qatadah, Ibrahim An-Nakha`i and others said. This meaning is clarified by Allah's statement,
﴿ لَا يَعۡلَمُونَ ٱلۡكِتَـٰبَ ﴾
(Who know not the Book) meaning, are they not aware of what is in it.
Ummi was one of the descriptions of the Prophet because he was unlettered. For instance, Allah said,
﴿ وَمَا كُنتَ تَتۡلُواْ مِن قَبۡلِهِۦ مِن كِتَـٰبٍ۬ وَلَا تَخُطُّهُ ۥ بِيَمِينِكَۖ إِذً۬ا لَّٱرۡتَابَ ٱلۡمُبۡطِلُونَ ﴾
(Neither did you (O Muhammad) read any book before it (this Qur'an) nor did you write any book (whatsoever) with your right hand. In that case, indeed, the followers of falsehood might have doubted) (29:48).
« إِنَّا أُمَّةٌ أُمِّيَّةٌ لَا نَكْتُبُ وَلَا نَحْسِبُ، الشَّهْرُ هكَذَا وَهكَذَا وَهكَذَا »
(We are an Ummi nation, neither writing nor calculating. The (lunar) month is like this, this and this (i.e. thirty or twenty-nine days.)
This Hadith stated that Muslims do not need to rely on books, or calculations to decide the timings of their acts of worship. Allah also said,
﴿ هُوَ ٱلَّذِى بَعَثَ فِى ٱلۡأُمِّيِّـۧنَ رَسُولاً۬ مِّنۡہُمۡ ﴾
(He it is Who sent among the Ummiyyin ones a Messenger (Muhammad) from among themselves) (62:2).
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