Musannaf Ibn Abi Shayba 19:422

Abu Bakr narrated to us, he said: Abd al-Salam narrated to us, from Ishaq ibn Abi Farwa, from Amr ibn Shu’ayb, from his father, that Mu’adh, Abdullah ibn Mas’ud, and Uqbah ibn Amir said: "If a prescribed punishment (hadd) becomes doubtful to you, then avert it."