Sahih Bukhari
Virtues of the Quran
Volume: 006 / Book Number: 061 / Hadith Number: 567
Narrated 'Abdullah bin Mughaffal:
I saw the Prophet reciting (Qur'an) while he was riding on his she camel or camel which was moving, carrying him. He was reciting Surat Fath or part of Surat Fath very softly and in an Attractive vibrating tone.