Musnad Ahmad 28:385

'Affan narrated to us, Hammad bin Salamah narrated to us, 'Amr bin Dinar informed us, from Suhayb al-Hadhdha', from 'Abdullah bin 'Amr, that the Messenger of Allah (may Allah bless him and grant him peace) said: "Whoever slaughters a sparrow without its right, Allah the Almighty will ask him about it on the Day of Resurrection." It was said: "And what is its right?" He said: "That he slaughters it, and does not take its neck and cut it off."