The last prophet of Islam was Prophet Muhammad (saw). The Quran was brought down to Mohammed, and he memorized it and also taught it to the Sahabah. Later, the Sunnah was the way of life on how to live as an example for the Muslims. Also, as a result, the Kafireen used to say that Mohammed wrote the Quran as a poem, and an evidence against that was that he was illiterate, meaning he could not read or write.