Musannaf Ibn Abi Shayba 16:168

Abu Bakr narrated to us, he said: Waki’ narrated to us, from Sufyan, from ‘Imran bin A’yan, from Abu Harb bin Abi al-Aswad, who said: Ibn Mas’ud was asked about a mouse that fell into ghee and died. He said: "Allah only forbade from the dead animal its meat and its blood."