Bukhari Hadith 1.3:”……suddenly the Truth descended upon him while he was in the cave of Hira. The angel came to him and asked him to read [Iqra]. The Prophet replied,
“I do not know how to read.”
The Prophet added, “The angel caught me (forcefully) and pressed me so hard that I could not bear it any more. He then released me and again asked me to read and I replied,
‘I do not know how to read.’
Thereupon he caught me again and pressed me a second time till I could not bear it any more. He then released me and again asked me to read but again I replied,
‘I do not know how to read (or what shall I read)?’
Thereupon he caught me for the third time and pressed me, and then released me and said,