Musannaf Ibn Abi Shayba 18:1262

Abu Bakr narrated to us, he said: Waki’ narrated to us, from Sufyan, from Qays ibn Muslim, from Tariq ibn Shihab, from al-Haytham ibn al-Aswad, from Abdullah ibn Amr: "Whoever gives it as charity, then it is an expiation for him." He said: "It wipes away from his sins the like of it."