Sahih Bukhari
Prophetic Commentary on the Quran (Tafseer of the Prophet (PBUH))
Volume: 006 / Book Number: 060 / Hadith Number: 480
Narrated 'Aisha:
The commencement of (the Divine Inspirations to) Allah's Apostle was in the form of true dreams. The Angel came to him and said, "Read! In the Name of your Lord Who has created all exists), has created man from a clot. Read! And your Lord is Most Generous, Who has taught (the writing) by the pen (the first person to write was Prophet Idris. (96.1-4)