Sahih al-Bukhari, Book 25, Hadith 215 (In-Book) ⓘ

Narrated `Abdullah bin `Amr bin Al-`As: I witnessed the Prophet 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 said, "Do it (now) and there is no harm in all these cases." Whenever the Prophet was asked about anything on that day, he replied, "Do it (now) and there is no harm in it."

حَدَّثَنَا سَعِيدُ بْنُ يَحْيَى بْنِ سَعِيدٍ، حَدَّثَنَا أَبِي، حَدَّثَنَا ابْنُ جُرَيْجٍ، حَدَّثَنِي الزُّهْرِيُّ، عَنْ عِيسَى بْنِ طَلْحَةَ، عَنْ عَبْدِ اللَّهِ بْنِ عَمْرِو بْنِ الْعَاصِ ـ رضى الله عنه ـ حَدَّثَهُ أَنَّهُ، شَهِدَ النَّبِيَّ صلى الله عليه وسلم يَخْطُبُ يَوْمَ النَّحْرِ، فَقَامَ إِلَيْهِ رَجُلٌ، فَقَالَ كُنْتُ أَحْسِبُ أَنَّ كَذَا قَبْلَ كَذَا‏.‏ ثُمَّ قَامَ آخَرُ فَقَالَ كُنْتُ أَحْسِبُ أَنَّ كَذَا قَبْلَ كَذَا حَلَقْتُ قَبْلَ أَنْ أَنْحَرَ، نَحَرْتُ قَبْلَ أَنْ أَرْمِيَ‏.‏ وَأَشْبَاهَ ذَلِكَ‏.‏ فَقَالَ النَّبِيُّ صلى الله عليه وسلم ‏ "‏ افْعَلْ وَلاَ حَرَجَ ‏" ‏‏.‏ لَهُنَّ كُلِّهِنَّ، فَمَا سُئِلَ يَوْمَئِذٍ عَنْ شَىْءٍ إِلاَّ قَالَ افْعَلْ وَلاَ حَرَجَ‏.‏