Hadith 2009
Sayyiduna Shaddad bin Aws (may Allah be pleased with him) said: I memorized two things from the Messenger of Allah (peace and blessings be upon him). He (peace be upon him) said: "Allah has prescribed excellence (i.e., mercy and justice) in everything. So when you kill (in retribution or jihad), do so quickly (do not prolong the killing), and when you slaughter an animal, slaughter it well. Let each one of you sharpen his knife and give comfort to his sacrificial animal (by slaughtering it swiftly), and do not subject it to torment."