Musnad Ahmad 28:13

Sufyan narrated to us, from al-Zuhri, from Isa ibn Talhah, from Abdullah ibn Amr ibn al-Aas, who said: A man said: "O Messenger of Allah, I shaved before I threw [the pebbles]." He said: "Throw, and there is no harm." And he said another time: "Before I slaughtered?" He said: "Slaughter, and there is no harm." He said: "I slaughtered before I threw." He said: "Throw, and there is no harm."