`Narrated by Ibn Abbas 
That Abu Bakr said, "O Messenger of Allah, verily your hair has turned gray.'' The Prophet replied,Surahs Hud, Al-Waqi`ah, Al-Mursalat, `Amma Yatasa'lun ﴿An-Naba'﴾ and Idhash-Shamsu Kuwwirat ﴿At-Takwir﴾ have turned my hair gray.)-Sunna Jami Al Tirmidhi Hadith No.3297