Muwatta Malik, Book 15, Hadith 473 (In-Book) ⓘ
Yahya related to me from Malik from Abdullah ibn Abi Bakr ibn Hazm that in a letter that the Messenger of Allah, may Allah bless him and grant him peace, sent to Amr ibn Hazm it said that no-one should touch the Qur'an unless he was pure.
حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ عَبْدِ اللَّهِ بْنِ أَبِي بَكْرِ بْنِ حَزْمٍ، . أَنَّ فِي الْكِتَابِ الَّذِي، كَتَبَهُ رَسُولُ اللَّهِ صلى الله عليه وسلم لِعَمْرِو بْنِ حَزْمٍ " أَنْ لاَ يَمَسَّ الْقُرْآنَ إِلاَّ طَاهِرٌ " .
also referenced under: Book 15, Hadith 1 (USC-MSA)