A mouse fell into the butter-fat and died. The Prophet ﷺ was asked about that. He said, "Throw away the mouse and the butter-fat that surrounded it, and eat the rest of the butter-fat (As-Samn).  

أَنَّ فَأْرَةً وَقَعَتْ فِي سَمْنٍ فَمَاتَتْ فَسُئِلَ النَّبِيُّ ﷺ عَنْهَا فَقَالَ أَلْقُوهَا وَمَا حَوْلَهَا وَكُلُوهُ قِيلَ لِسُفْيَانَ فَإِنَّ مَعْمَرًا يُحَدِّثُهُ عَنِ الزُّهْرِيِّ عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ عَنْ أَبِي هُرَيْرَةَ قَالَ مَا سَمِعْتُ الزُّهْرِيَّ يَقُولُ إِلاَّ عَنْ عُبَيْدِ اللَّهِ عَنِ ابْنِ عَبَّاسٍ عَنْ مَيْمُونَةَ عَنِ النَّبِيِّ ﷺ وَلَقَدْ سَمِعْتُهُ مِنْهُ مِرَارًا  

regarding an animal, e.g., a mouse or some other animal that had fallen into solid or liquid oil or butter-fat: I had been informed that a mouse had died in butter-fat whereupon Messenger of Allah ﷺ ordered that the butter-fat near it be thrown away and the rest of the butter-fat can be eaten.  

عَنِ الدَّابَّةِ تَمُوتُ فِي الزَّيْتِ وَالسَّمْنِ وَهْوَ جَامِدٌ أَوْ غَيْرُ جَامِدٍ الْفَأْرَةِ أَوْ غَيْرِهَا قَالَ بَلَغَنَا أَنَّ رَسُولَ اللَّهِ ﷺ أَمَرَ بِفَأْرَةٍ مَاتَتْ فِي سَمْنٍ فَأَمَرَ بِمَا قَرُبَ مِنْهَا فَطُرِحَ ثُمَّ أُكِلَ عَنْ حَدِيثِ عُبَيْدِ اللَّهِ بْنِ عَبْدِ اللَّهِ  

The Prophet ﷺ was asked about a mouse that had fallen into butter-fat (and died). He said, "Throw away the mouse and the portion of butter-fat around it, and eat the rest."  

سُئِلَ النَّبِيُّ ﷺ عَنْ فَأْرَةٍ سَقَطَتْ فِي سَمْنٍ فَقَالَ أَلْقُوهَا وَمَا حَوْلَهَا وَكُلُوهُ