This is a question on how the Quran is preserved if Hazrat Usman ( RadiAllahhu an) ordered the burning of the copies of the Quran in his caliphate. Hadith in mention is as follows :
Bukhari: vol. 6, hadith 510, pp. 478-479; book 61
Narrated Anas bin Malik:
Hudhaifa bin Al-Yaman came to Uthman at the time when the people of Sham and the people of Iraq were Waging war to conquer Arminya and Adharbijan. Hudhaifa was afraid of their (the people of Sham and Iraq) differences in the recitation of the Qur'an, so he said to 'Uthman, "O chief of the Believers! Save this nation before they differ about the Book (Quran) ..." So 'Uthman sent a message to Hafsa saying, "Send us the manuscripts of the Qur'an so that we may compile the Qur'anic materials in perfect copies and return the manuscripts to you." Hafsa sent it to 'Uthman. 'Uthman then ordered Zaid bin Thabit, 'Abdullah bin AzZubair, Said bin Al-As and 'AbdurRahman bin Harith bin Hisham to rewrite the manuscripts in perfect copies. 'Uthman said to the three Quraishi men, "In case you disagree with Zaid bin Thabit on any point in the Qur'an, then write it in the dialect of Quraish, the Qur'an was revealed in their tongue." They did so, and when they had written many copies, 'Uthman returned the original manuscripts to Hafsa. 'Uthman sent to every Muslim province one copy of what they had copied, and ordered that all the other Qur'anic materials, whether written in fragmentary manuscripts or whole copies, be burnt. ..."
This is a lecture on 'Al Quran- the Miracle of Miracles' and the second part is from the question and answer session from the debate between sheikh ahmed deedat and jimmy swaggart. Ahmed Deedat explains to us the miracle that can be found in the numberings of the letters of the Quran. There is a mathematical preservation of the Quran by Allah Almighty.
What he is saying is if the Quran had been altered in any way, the miracle count would have been distorted.
In Fact, Hazrat Usman (ra) only ordered all other copies to be burnt as sign of respect as in Islam we don't discard the words of Quran in fact we burn them to save it from being getting into unwanted places.
