Shaddad ibn Aws reported: The Messenger of Allah, peace and blessings be upon him, said, “Verily, Allah has prescribed excellence in everything. So if you have to kill, then kill in the best manner. If you slaughter, then slaughter in the best manner. Let one of you sharpen his knife so his animal feels no pain.”

Source: Sahih Muslim 1955

Grade: Sahih (authentic) according to Muslim

شَدَّادِ بْنِ أَوْسٍ قَالَ ثِنْتَانِ حَفِظْتُهُمَا عَنْ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ إِنَّ اللَّهَ كَتَبَ الْإِحْسَانَ عَلَى كُلِّ شَيْءٍ فَإِذَا قَتَلْتُمْ فَأَحْسِنُوا الْقِتْلَةَ وَإِذَا ذَبَحْتُمْ فَأَحْسِنُوا الذَّبْحَ وَلْيُحِدَّ أَحَدُكُمْ شَفْرَتَهُ فَلْيُرِحْ ذَبِيحَتَهُ

1955 صحيح مسلم كتاب الصيد والذبائح وما يؤكل من الحيوان باب الأمر بإحسان الذبح والقتل وتحديد الشفرة