Narrated `Abdullah bin `Amr bin Al `Aas:

Allah's Messenger (s.a.w.a.) stopped at Mina during his last Hajj for the people and they were asking him questions. A man came and said, "I forgot and got my head shaved before slaughtering the sacrificing animal." The Prophet (s.a.w.a.) said, "There is no harm, go and do the slaughtering now." Then another person came and said, "I forgot and slaughtered (the camel) before Rami (throwing the pebbles at  Jamaraat)." The Prophet (s.a.w.a.) said, "Do the Rami now and there is no harm." The narrator added: So on that day, whenever the Prophet (s.a.w.a.) was asked about anything (as regards the ceremonies of Hajj) performed before or after its due time, his reply was: "Do it (now) and there is no harm."

Narrated `Abdullah bin `Amr bin Al-`As:

I witnessed the Prophet (s.a.w.a.) when he was delivering the sermon on the Day of Nahr. A man stood up and said, "I thought that such and such was to be done before such and such. I got my hair shaved before slaughtering." (Another said), "I slaughtered the Hadi before doing the Rami." So, the people asked about many similar things. The Prophet (s.a.w.a.) said, "Do it (now) and there is no harm in all these cases." Whenever the Prophet (s.a.w.a.) was asked about anything on that day, he replied, "Do it (now) and there is no harm in it."

Narrated to us: Yahya ibn Yahya, he said, I said to Malik, from ibn Shahab from Isa ibn Talha ibn Ubaidullah from Abdullah b. 'Amr b. al-'Aas said that Allah's Messenger (s.a.w.a.) stopped during the Farewell Pilgrimage at Mina for people who had something to ask. A man came and said: O Messenger of Allah (s.a.w.a.), I was not aware and I shaved before sacrificing, whereupon he (s) said: Now sacrifice (the animal) and there is no harm (for you). Then another man came and he said: O Messenger of Allah (s.a.w.a.), I was not aware and I sacrificed before throwing the pebbles, whereupon he (s) said: (Now) throw the pebbles, and there is no harm (for you). Allah's Messenger (s.a.w.a.) was not asked about anything which had been done before or after (its proper time) but he said: Do it, and no harm is there (for you).