Bulugh al-Maram 766
'Abdullah Ibn ‘Amro bin al-’As (RAA) narrated that the Messenger of Allah (ﷺ) stood in Mina during the Farewell Hajj, while the people asked him questions and he answered them. A man asked, ‘O Prophet of Allah! I was not alert and I shaved my head before slaughtering my animal?’ The Prophet (ﷺ) said:
“There is no harm, go and slaughter your animal." Another man asked, ‘l slaughtered the animal before I threw the pebbles? Prophet (ﷺ) said: “There is no harm, go and throw your pebbles." The narrator said: "Whoever asked the Prophet (ﷺ) about anything done before or after the other he told him "No harm done. Go and do (whatever you missed)." Agreed upon.
وَعَنْ عَبْدِ اَللَّهِ بْنِ عَمْرِوِ بْنِ اَلْعَاصِ رَضِيَ اَللَّهُ عَنْهُمَا { أَنَّ رَسُولَ اَللَّهِ ‏- صلى الله عليه وسلم ‏-وَقَفَ فِي حَجَّةِ اَلْوَدَاعِ, فَجَعَلُوا يَسْأَلُونَهُ, فَقَالَ رَجُلٌ: لَمْ أَشْعُرْ, فَحَلَقْتُ قَبْلَ أَنْ أَذْبَحَ.‏ قَالَ: " اِذْبَحْ وَلَا حَرَجَ " فَجَاءَ آخَرُ, فَقَالَ: لَمْ أَشْعُرْ, فَنَحَرْتُ قَبْلَ أَنْ أَرْمِيَ, قَالَ: " اِرْمِ وَلَا حَرَجَ " فَمَا سُئِلَ يَوْمَئِذٍ عَنْ شَيْءٍ قُدِّمَ وَلَا أُخِّرَ إِلَّا قَالَ: " اِفْعَلْ وَلَا حَرَجَ " }  مُتَّفَقٌ عَلَيْهِ.‏  1‏ .‏‏1 ‏- صحيح.‏ رواه البخاري ( 83 )‏، ومسلم ( 1306 )‏.‏