Narrated Ibn Az-Zubair:
I said to ‘Uthman, “This Verse which is in Surat-al-Baqara:
“Those of you who die and leave widows behind…without turning them out.” has been abrogated by another Verse. Why then do you write it (in the Qur’an)?” ‘Uthman said. “Leave it (where it is), O the son of my brother, for I will not shift anything of it (i.e. the Quran) from its original position.”
Sahih Bukhari, Volume 6, Book60, Number 60