" إِنَّ اللَّهَ عَزَّ وَجَلَّ كَتَبَ الإِحْسَانَ عَلَى كُلِّ شَىْءٍ فَإِذَا قَتَلْتُمْ فَأَحْسِنُوا الْقِتْلَةَ وَإِذَا ذَبَحْتُمْ فَأَحْسِنُوا الذِّبْحَةَ لِيُحِدَّ أَحَدُكُمْ شَفْرَتَهُ وَلْيُرِحْ ذَبِيحَتَهُ "
It was narrated that Shaddad bin Aws said: "Two things that I memorized form the Messenger of Allah; 'Allah, the Mighty and Sublime, has decreed proficiency in all things, so when you kill, kill well, and when you slaughter, slaughter well. Let one of you sharpen his blade and spare suffering to the animal he slaughter,"" (Sahih )