Sunan Ibn Majah Book 27, Hadith 3178

حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ نُمَيْرٍ، حَدَّثَنَا عُمَرُ بْنُ عُبَيْدٍ الطَّنَافِسِيُّ، عَنْ سَعِيدِ بْنِ مَسْرُوقٍ، عَنْ عَبَايَةَ بْنِ رِفَاعَةَ، عَنْ جَدِّهِ، رَافِعِ بْنِ خَدِيجٍ قَالَ كُنَّا مَعَ رَسُولِ اللَّهِ ـ صلى الله عليه وسلم ـ فِي سَفَرٍ فَقُلْتُ يَا رَسُولَ اللَّهِ إِنَّا نَكُونُ فِي الْمَغَازِي فَلاَ يَكُونُ مَعَنَا مُدًى فَقَالَ ‏ "‏ مَا أَنْهَرَ الدَّمَ وَذُكِرَ اسْمُ اللَّهِ عَلَيْهِ فَكُلْ غَيْرَ السِّنِّ وَالظُّفْرِ فَإِنَّ السِّنَّ عَظْمٌ وَالظُّفْرَ مُدَى الْحَبَشَةِ ‏"‏ ‏.‏

It was narrated that Rafi’ bin Khadij said:“We were with the Prophet (ﷺ) on a journey, and I said: ‘O Messenger of Allah, we are (sometimes) on military campaigns, and we have no knife with us.’ He said: ‘(Use) whatever causes the blood to flow, mention the Name of Allah and eat, but (do not use) teeth or nails, for the tooth is a bone and the nail is the knife of the Ethiopians.”