On the authority of Abu Ya'la Shaddad bin Aws (may Allah be pleased with him), that the Messenger of Allah (peace and blessings of Allah be upon him) said:
Verily Allah has prescribed ihsan (proficiency, perfection) in all things. So if you kill then kill well; and if you slaughter, then slaughter well. Let each one of you sharpen his blade and let him spare suffering to the animal he slaughters."[Muslim] (DE)
Reference (DE): 40 Hadith Nawawi 17 (DE)
English translation (DE): Hadith 17 (DE)