The Quran

هُوَ الَّذي بَعَثَ فِي الأُمِّيّينَ رَسولًا مِنهُم يَتلو عَلَيهِم آياتِهِ وَيُزَكّيهِم وَيُعَلِّمُهُمُ الكِتابَ وَالحِكمَةَ وَإِن كانوا مِن قَبلُ لَفي ضَلالٍ مُبينٍ

Muhammad Asad

He it is who has sent unto the unlettered people an apostle from among themselves,¹ to convey unto them His messages, and to cause them to grow in purity, and to impart unto them the divine writ as well as wisdom - whereas before that they were indeed, most obviously, lost in error -;

The term "unlettered people" (ummiyun) denotes a nation or community who had not previously had a revealed scripture of their own (Razi). The designation of the Prophet as a man "from among themselves" is meant, in this context, to stress the fact that he, too, was unlettered (ummi) in the primary sense of this word (cf. 7:157 and 158)., and could not, therefore, have "invented" the message of the Qur'an or "derived" its ideas from earlier scriptures.