Sunnah.com reference : Book 12, Hadith 24English translation : Book 12, Hadith 1382Arabic reference : Book 12, Hadith 1342
Shaddad bin Aus (RAA) narrated that the Messenger of Allah (ﷺ) said:
"Verily, Allah has prescribed proficiency in all things. Thus, if you kill, kill in the least painful manner you can; and when you slaughter an animal, do it in the best possible way; and any of you should sharpen his blade so that the animal may be spared from the suffering of the slaughtering."
وَعَنْ شَدَّادِ بْنِ أَوْسٍ ‏- رضى الله عنه ‏- قَالَ: قَالَ رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏-{ 
" إِنَّ اَللَّهَ كَتَبَ اَلْإِحْسَانَ عَلَى كُلِّ شَيْءٍ, فَإِذَا قَتَلْتُمْ فَأَحْسِنُوا اَلْقِتْلَةَ, وَإِذَا ذَبَحْتُمْ فَأَحْسِنُوا اَلذِّبْحَةَ, وَلْيُحِدَّ أَحَدُكُمْ شَفْرَتَهُ, وَلْيُرِحْ  (1756)‏ ذَبِيحَتَهُ" }  رَوَاهُ مُسْلِمٌ  (1757)‏ .‏‏3 ‏- كذا "بالأصلين" ، وفي "الصحيح" : " فليرح".‏‏4 ‏- صحيح.‏ رواه مسلم ( 1955 )‏.‏