Musnad Ahmad 28:324

'Abd al-Rahman narrated to us, Malik ibn Anas narrated to us, from al-Zuhri, from 'Isa ibn Talhah, from 'Abdullah ibn 'Amr: That a man said, "O Messenger of Allah, I did not realize; I slaughtered before I threw [the pebbles]?" He said, "Throw, and there is no harm." Another said, "O Messenger of Allah, I shaved before I slaughtered?" He said, "Slaughter, and there is no harm." He was not asked on that day about anything that was done out of order or delayed, except that he said, "Do it, and there is no harm."