[12].Surah Yusuf [Joseph]: Ayat 3

Ayat 3. We relate unto you (Muhammad  [SAWW](PBUH) the best of stories through Our Revelations unto you, of this Qur'an. And before this (i.e. before the coming of Divine Inspiration to you), you were among those who knew nothing about it (the Qur'an).  

Hazrat Ibn Abbas (May Allah be pleased with them) reported: The Messenger of Allah  [SAWW](PBUH) said, "He who does not memorize any part from the Qur'an he is like the ruined house.''  

[At-Tirmidhi Hadith # 2913] 

Lesson : as mentioned above in Surah Yusuf Ayat 3. you were among those who knew nothing about it (the Qur'an)" This Hadith means that the heart of that Muslim is devoid of grace of spiritualism and Grace of Allah who does not remember by heart any portion of the Qur'an, in the same way as a deserted house is deprived of inhabitants and Blessings of Allah. What we learn from this is that every Muslim must remember some portion of the Qur'an so that he is safe from the admonition mentioned in this Hadith.