Musannaf Ibn Abi Shayba 1:1219

Abu Bakr narrated to us, he said: Humayd ibn Abd al-Rahman narrated to us, from Hasan ibn Salih, from Jabir, from Amir and Salim, they both said: "A man who is in a state of major ritual impurity (junub) should not touch dirhams that have the Book of Allah written upon them." He said: And Ata and al-Qasim said: "He may touch them if they are wrapped in a cloth."