Narrated Shaddad b. Aws: There are two characteristics that I heard the Messenger of Allah (ﷺ) say: Allah has decreed that everything should be done in a good way, so when you kill use a good method. The version of the narrators other than Muslim says: "So kill in a good manner." And when you slaughter, you should use a good method, for one of you should sharpen his knife, and give the animal as little pain as possible.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا مُسْلِمُ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا شُعْبَةُ، عَنْ خَالِدٍ الْحَذَّاءِ، عَنْ أَبِي قِلاَبَةَ، عَنْ أَبِي الأَشْعَثِ، عَنْ شَدَّادِ بْنِ أَوْسٍ، قَالَ خَصْلَتَانِ سَمِعْتُهُمَا مِنْ، رَسُولِ اللَّهِ صلى الله عليه وسلم " إِنَّ اللَّهَ كَتَبَ الإِحْسَانَ عَلَى كُلِّ شَىْءٍ فَإِذَا قَتَلْتُمْ فَأَحْسِنُوا " . قَالَ غَيْرُ مُسْلِمٍ يَقُولُ " فَأَحْسِنُوا الْقِتْلَةَ وَإِذَا ذَبَحْتُمْ فَأَحْسِنُوا الذَّبْحَ وَلْيُحِدَّ أَحَدُكُمْ شَفْرَتَهُ وَلْيُرِحْ ذَبِيحَتَهُ " .
sunnah.com