Sahih Bukhari
Prophetic Commentary on the Quran (Tafseer of the Prophet (PBUH))
Volume: 006 / Book Number: 060 / Hadith Number: 479
Narrated Aisha:
The commencement of the Divine Inspiration 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 that exists), has created man a clot. Read! And your Lord is Most Generous" ..(96.1,2,3)