Musannaf Ibn Abi Shayba 16:164

Abu Bakr narrated to us, he said: Muhammad ibn Fudayl narrated to us, from ‘Ata’ ibn al-Sa’ib, from Maysarah, from ‘Ali, regarding a mouse that falls into ghee: He said: "If it is melted, then pour it out. And if it is solid, then throw it away and what is around it, and eat the rest of it."