From Sahih Bukhari (Hadith 5047):
Narrated `Abdullah bin Mughaffal:I saw the Prophet (ﷺ) 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
Reference: Bukhari 5047